UNIVERSITY   OF    CALIFORNIA 

COLLEGE    OF   AGRICULTURE 

AGRICULTURAL    EXPERIMENT   STATION 

BERKELEY,    CALIFORNIA 

CIRCULAR  313 

April,  1928 

FRUIT  JUICES  AND  FRUIT  JUICE 
BEVERAGES 

JOHN  H.  IRISHi 


UNFERMENTED   FRUIT  JUICES 

During  recent  years  the  production  of  fruit  juices  has  very 
greatly  increased.  Several  factors  have  been  responsible  for  this 
rapid  development,  the  most  important  being  improvements  in  the 
quality  of  the  finished  products,  effective  advertising  and  the  enforce- 
ment of  prohibition. 

Because  of  the  increased  market  for  these  products  there  has 
arisen  an  insistent  demand  for  information  on  the  methods  of  manu- 
facture, and  the  purpose  of  this  publication  is  to  furnish  practical 
directions  for  the  preparation  of  fruit  juices  and  fruit  juice  beverages. 
The  contents  are  based  on  Circular  220  and  Bulletin  359,  California 
Agricultural  Experiment  Station,  both  publications  being  now  out 
of  print.  This  is  supplemented  by  the  results  of  later  investiga- 
tions made  by  the  Fruit  Products  Laboratory  of  the  University  of 
California. 

A  pure  fruit  juice  may  be  defined  as  a  natural  juice  pressed  from 
the  fruit  and  practically  unaltered  in  composition  during  preparation 
and  preservation. 

A  fruit  juice  beverage  may  be  defined  as  a  fruit  juice  considerably 
altered  in  composition  before  consumption.  It  is  usually  a  juice 
diluted  with  water  and  sweetened  with  sugar.  The  beverage  may  or 
may  not  be  charged  with  carbonic  acid  gas.  Examples  of  fruit  juice 
beverages  are  orangeade,  lemonade  and  bottled  strawberry  soda  water. 


i  Junior  Chemist  in  the  Experiment  Station. 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


GENERAL    PRINCIPLES 

Any  fruit  juice  is  best  when  it  is  first  pressed  from  the  fresh 
fruit.  Treatment  that  may  be  given  it  thereafter  usually  injures  its 
delicate  flavor  and  aroma,  and  the  most  important  problem  in  prepa- 
ration is  that  of  retaining  in  the  finished  product  as  much  as  possible 
of  the  pleasing  qualities  of  the  fresh  juice.  It  is  possible  to  improve 
its  appearance  by  making  it  clearer,  but  not  to  improve  upon  the 
natural  flavor. 

Preservation. — Fresh  fruit  juices  soon  spoil  couqoletely  through 
fermentation  or  molding,  if  nothing  is  done  to  destroy  or  prevent  the 
growth  of  yeasts  and  molds.  These  are  easily  killed  by  temperatures 
between  160°  and  175°  Fahrenheit,  and  if  the  juice  is  hermetically 
sealed,  before  sterilization  by  heat,  it  will  not  spoil  so  long  as  the 
container  remains  sealed  against  the  entrance  of  living  yeasts  or 
molds. 

Sterilizing  fruit  juices  at  temperatures  below  212°  F  is  commonly 
termed  pasteurization  and  is  the  most  generally  used  process  of 
preservation.  Investigations  have  shown  that  common  pasteurizing 
temperatures  do  not  destroy  all  microorganisms  present  in  fruit 
juices.  Spore  bearing  bacteria  often  survive  but  are  incapable  of 
growing  in  the  acid  fruit  juice  and  hence  do  not  cause  spoiling. 
Yeasts,  molds  and  vinegar  bacteria  are  destroyed  by  the  pasteurizing 
temperatures  recommended  in  this  circular  and  therefore  juices  so 
treated  and  subsequently  protected  from  reinfection  do  not  spoil. 
Too  high  a  temperature  of  pasteurizing  or  too  long  a  period  of  heat- 
ing injures  the  fresh  fruit  flavor  and  imparts  a  cooked  taste. 

Juices  held  in  cold  storage  at  32°  F,  or  above,  will  in  time  (six 
months  or  less)  spoil;  but  if  maintained  in  the  frozen  condition  at 
temperatures  below  32°  F  will  keep  indefinitely.  The  flavor  is  only 
slightly  impaired  by  such  treatment,  provided  the  juices  are  stored 
in  sealed  containers  to  prevent  volatilization  of  aromatic  principles 
and  to  prevent  the  absorption  of  disagreeable  odors  and  flavors. 
This  method  of  preservation  has  been  tested  commercially  and 
appears  to  have  great  possibilities, 

Chemical  preservatives  were  at  one  time  used  freely  to  preserve 
fruit  juices  but  are  now  less  popular.  Sodium  benzoate  is  the  most 
commonly  used  of  these  preservatives  and  is  allowed  by  law  if 
declared  on  the  label.  Sulfurous  acid  is  used  to  preserve  grape  juice 
for  special  purposes,  where  it  is  to  be  kept  a  short  time,  but  not  for 
permanent  preservation. 


CIRC.  313]  FRUIT    JUICES   AND   FRUIT    JUICE   BEVERAGES  3 

If  bottles  and  corks  are  sterilized  and  handled  without  contamina- 
tion, and  if  the  juice  is  filtered  perfectly  clear,  thus  practically  free- 
ing- it  of  molds  and  yeasts,  it  is  possible  to  preserve  juices  in  bottles 
with  heavy  pressures  of  carbon  dioxide  without  use  of  heat  or 
chemical  preservatives.  Juices  so  preserved  are  superior  in  flavor  to 
pasteurized  juices,  but  the  method  has  not  been  satisfactory  in  prac- 
tice because  of  the  difficulty  in  avoiding  contamination  of  the  juice 
with  molds  and  yeasts.     Spoilage  losses  are  excessive. 

Treatment  of  juices  with  ultra-violet  light  has  not  been  very  suc- 
cessful as  a  means  of  sterilization — although  it  is  said  to  sterilize 
water.  Recently  electrolysis  of  juices  has  been  advocated  for 
sterilization  but  this  has  not  proven  satisfactory. 

Clearing  the  Juice. — In  addition  to  preserving  the  juice  against 
fermentation  and  molding;  it  is  desirable  to  improve  the  appearance 
by  making  it  as  clear  as  possible.  Filtration  is  the  most  common  and 
also  the  most  satisfactory  method.  Clearing  by  centrifugal  force 
and  clarification  by  finings  (clarifying  materials)  are  also  used.  The 
latter  process  consists  in  adding  to  the  juice  some  substance  such  as 
white  of  egg  or  casein  which  coagulates  and  settles  to  the  bottom  of 
the  container,  carrying  down  the  particles  of  pulp  and  other  solids 
responsible  for  the  cloudiness  of  the  juice. 

The  use  of  a  small  proportion  of  moldy  or  soured  fruit  will  spoil 
the  flavor  of  a  large  volume  of  juice.  Only  sound,  clean  fruit  should 
be  used  and  all  fruit  should  be  carefully  sorted.  Only  clean  press 
cloths,  pumps,  sterilizers,  filters,  and  containers  can  be  employed  if 
the  quality  of  the  product  is  not  to  be  injured.  Cleaning  and  steriliz- 
ing such  equipment  with  hot  water  and  steam  is  desirable.  Press 
cloths  and  other  equipment  should  be  kept  dry  when  not  in  use. 


EQUIPMENT    USED    IN    FRUIT   JUICE    PREPARATION 

Most  of  the  equipment  used  in  fruit  juice  manufacture  has  been 
developed  in  other  industries,  notably  in  wine  making,  brewing,  and 
vinegar  making.  The  most  common  forms  of  such  equipment  will 
be  described  briefly  and  illustrated.  More  complete  descriptions  may 
be  had  from  dealers  and  manufacturers,  a  list  of  which  is  found  at 
the  end  of  this  circular.  A  typical  layout  of  plant  for  preparing 
fruit  juices  is  illustrated  in  figure  20  and  an  outline  of  processes  is 
shown  in  figure  30.  An  estimated  cost  of  equipment  is  given  in 
table  1. 


4  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

Sorting  Equipment. — Broad,  heavy  woven  endless  cotton  or  rub- 
ber belts  which  carry  the  fruit  to  be  sorted  slowly  past  the  sorters  are 
often  used  in  canneries  and  evaporators  for  sorting"  purposes  and  may 
be  used  to  advantage,  especially  with  apples,  in  sorting  fruit  for 
juice  manufacture.  Belts  made  of  metal  cloth  similar  to  ordinary 
metal  door  matting  are  very  satisfactory  because  they  may  be  easily 
washed  and  may  be  fitted  with  sprays  at  one  end  for  washing  the 
sorted  fruit.  Such  equipment  is  obtainable  from  any  cannery  supply 
company. 

TABLE  1 

Approximate  Cost  of  Equipment  for  Preparation  of  Fruit  Juices 
(Data,  courtesy  of  The  Hydraulic  Press  Mfg.  Co.) 


Ten-hour  day  capacity 

Sorter 

Rotary  apple  washer 

Press  with  elevator  and  grinder 

Filtering,  bottling  and  pasteuriz- 
ing outfits 

Line  shaft  and  belting  (press  and 
filtering  outfit) 

Boiler  and  stack* 

Steam  and  water  piping 

Roller  conveyor  track 

Approximate  total  price  of  equip- 
ment f.o.b.  factory j 

Approximate  cost  of  installing  ma- 
chinery  

Size,  press  room 

Room  for  filtering,  bottling,  etc 

Size,  boiler  room 


200  gals. 


$270.00 
360.00 
420.00 

1,315.00 

100  00 

400.00 

105.00 

41  50 

3,011.50 

100.00 
10'xl2'x8' 
18'x24'x9' 
14'x  18'x  9 


250  gals. 


$270.00 
360.00 
420  00 

1,730  00 

100.00 

400.00 

105.00 

41.50 

3,426.50 

100.00 
10'xl2'x8' 
18'x24'x9' 
14'xl8'x9' 


500  gals. 


$270.00 
360.00 
525.00 

2,265.00 

100.00 
400  00 
105  00 

72.00 

4,097.00 

100.00 
12'xl6'xl0' 
20'x32'xl0' 
14'xl8'xl0' 


750  gals. 


$270.00 
360.00 
715  00 

2,571.00 

100.00 
400.00 
105.00 


4,521.00 

120.00 
14'x20'xl0' 
20'x36'xl0' 
14'xl8'xl0' 


1,000  gals 


$270  00 
360.00 
715.00 

2,976.00 

100.00 
400  00 
105  00 


4,926  00 

120.00 
14'x  20'x  10'. 
22'x40'xl0' 
14'x  18'x  10' 


1,500  gals. 


$270  00 
360.00 
925.00 

3,930.00 

100.00 
500.00 
120  00 


6,230.00 

150.00 
16'x22'xll' 
24'x44'xl0' 
14'x  18'x  10' 


*  Based  on  10-horsepower  boiler  with  the  exception  of  that  for  1,500-gallons  capacity,  where  15-horse- 
power  equipment  will  be  needed. 

t  Does  not  include  cost  of  building.    This  can  be  estimated  from  dimensions  of  the  rooms. 

Washing  Equipment. — Fruit  often  arrives  at  the  factory  very 
dusty  or  soiled  from  contact  with  spoiled  fruit.  It  will  generally 
improve  the  quality  of  the  product  to  wash  the  fruit  before  crushing. 
The  most  effective  washing  device  for  fruits  that  will  withstand  rough 
treatment  is  the  rotary  tomato  washer,  shown  in  figure  1.  Berries 
will  not  stand  rough  treatment  and  must  either  be  rinsed  by  hand  or 
washed  under  a  gentle  spray  of  water. 

Crushers. — The  most  satisfactory  type  of  crusher  for  general  use 
is  that  commonly  used  for  apples  under  the  name  of  ' '  apple  grater. ' ' 
It  consists  of  a  cylinder  on  the  surface  of  which  are  fixed  short  knives 
working  against  a  corrugated  plate.  In  addition  there  is  sometimes 
a  set  of  concave  or  upright  knives,  against  which  the  cylinder  revolves. 


ClRC.  313]  FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES 


Fig.  1. — Rotary  spray  washer  for  fruits.   (Courtesy  of  Anderson-Barngrover  Co.) 


f 

P  in.  r 

y 

If    ill  It  % 

^ 

I  -    * 

Fig.  2. — Large  size  grape  crusher  and  stemmer 
(Courtesy,  California  Press  Mfg.  Co.) 


6 


UNIVERSITY    OP    CALIFORNIA EXPERIMENT    STATION 


The  fruit  is  grated  or  crushed  between  the  plate  or  concave  and 
the  cylinder.  The  upright  knives  or  the  corrugated  plate  are  fixed 
to  strong  springs  in  order  that  the  crusher  will  have  flexibility  and 
not  be  broken  by  pieces  of  wood  or  stone  which  may  accidentally  fall 
into  the  crusher. 


Fig.  3. — Farm  size  grape  crusher  and  press. 
(Courtesy,  Hydraulic  Press  Mfg.  Co.) 

For  grapes,  the  best  crusher  consists  of  two  corrugated  or  fluted 
metal  rollers  which  revolve  close  together  and  toward  each  other, 
carrying  downward  between  them,  and  crushing  the  grapes  that  are 
fed  into  a  hopper  above  (fig.  2).  Connected  with  the  crusher  is  a 
stemmer  consisting  of  a  horizontal  metal  cylinder  with  perforated 
bottom,  through  which  the  grapes  are  forced  by  revolving  paddles. 
The  stems  cannot  pass  through  these  openings  and  are  thrown  out 
at  the  end  of  the  crusher.  Grapes  for  red  juice  should  be  stemmed, 
those  for  white  juice  need  not  be  stemmed. 


Circ.  313] 


FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES 


For  farm  use,  small  hand-power  crushers,  usually  with  a  press 
mounted  on  the  same  frame,  are  available  (fig.  3).  These  are  designed 
either  for  grapes  or  for  apples,  but  the  apple  crusher  style  will  find 
the  greatest  application,  being  suited  to  both  apples  and  soft  fruits. 
A  satisfactory  combined  crusher  and  press  for  home  use  is  shown  in 
figure  4. 

Presses. — The  press  known  as  the  "rack  and  cloth"  press  will 
give  a  higher  yield  and  a  clearer  juice  than  will  the  basket  press. 
In  the  rack  and  cloth  press  the  crushed  fruit  is  built  up  in  layers  in 


Fig.  4. — Small  combination  crusher  and  press  suitable  for  household 
scale  production  of  fruit  juices. 


heavy  press  cloths  between  racks  made  of  wooden  slats.  Pressure  is 
ordinarily  applied  by  means  of  a  ram  operated  by  a  hydraulic  pump, 
although  cog  gears  are  often  used.  The  press  is  usually  attached 
to  the  same  frame  as  the  crusher  (fig.  5). 

In  basket  presses  the  cloths  and  racks  are  not  used.  The  crushed 
fruit  is  held  in  a  strongly  reinforced  wooden  basket  of  cylindrical 
shape,  which  rests  on  the  press  floor.  The  basket  is  movable. 
Pressure  is  applied  by  a  lever  and  screw  in  small  presses  and  by 
hydraulic  pressure  in  the  larger  presses   (fig.  6). 

A  homemade  press  can  be  made  of  farm  equipment  arranged  as 
shown  in  figure  7.  It  can  be  used  either  with  racks  and  cloths  as 
illustrated  or  with  a  basket. 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


Fig.  5. — Large  size  apple  grater  and  press. 
(Courtesy,  Hydraulic  Press  Mfg.  Co.) 


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Fig.  6. — Basket  type  hydraulic  press,  suitable  for  grapes. 
(Courtesy,  California  Press  Mfg.  Co.) 


Cute.  313 


FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES 


Pasteurizers  for  Juice  in  Bulk. — Most  juices  before  filtering  should 
be  heated  to  coagulate  proteins  and  gums  which  would  otherwise 
precipitate  in  the  bottle  and  cause  cloudiness.  Grape  juice  is  usually 
sterilized  and  stored  several  months  to  permit  separation  of  cream 
of  tartar  before  bottling.  This  sterilization  is  accomplished  on  a 
large  scale  by  use  of  some  one  of  the  pasteurizers  described  in  this 
section. 


Fig.  7. — Home  made  fruit  juice  press.  Also  suitable  for  pressing  olives  for 
oil.  A,  heavy  wagon  or  automobile  jack;  B,  light  steel  cable  or  one- inch  rope; 
C,  two  pieces  2"  X  24"  X  24" ;  D,  tin-lined  sheet  metal  pan,  30"  X  30"  X  3"  with 
juice  spout  as  shown;  or  wooden  trough  of  same  dimensions;  E,  heavy  burlap  to 
hold  fruit;  F,  3"  or  2"  floor;  G,  frame  of  2"  X  6"  pine. 

For  the  purposes  of  this  circular  the  terms  "  pasteurization ' '  and 
"sterilization"  are  loosely  used  and  sometimes  interchangeably,  since 
they  are  so  employed  in  the  industry ;  furthermore  the  high  tempera- 
tures commonly  used  for  complete  sterilization  are  not  needed  with 
fruit  juices. 

A  very  common  and  effective  sterilizer  consists  of  a  block  tin  or 
aluminum  pipe  surrounded  by  a  steam  jacket.  The  juice  flows 
through  the  inner  pipe  and  steam  admitted  to  the  jacket  heats  the 
juice  to  any  desired  temperature.  A  thermometer  at  the  juice  outlet 
is  necessary  for  control  of  temperature.  The  hot  juice  may  be 
delivered  by  means  of  a  hose  to  the  final  containers,  in  place  on 
shelves  or  racks  (fig.  8). 


10 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


Fig1.  8. — Steam  heated  continuous  pasteurizer  for  fruit  juices.  A,  juice  valve; 
B,  steam  valve  for  occasional  flushing  out  of  juice  pipe;  C,  juice  inlet;  D,  to 
sewer;  E,  to  steam  trap;  F,  steam  inlet;  G,  thermometer;  H,  juice  outlet. 
(Courtesy,  Hydraulic  Press  Mfg.  Co.) 

An  objection  sometimes  made  to  this  pasteurizer  is  that  the  juice 
in  contact  with  the  walls  of  the  pasteurizer  may  be  overheated  and 
cooked  taste  be  imparted  to  the  juice.  This  is  prevented  if  the  juice 
pipe  is  surrounded  by  hot  water  instead  of  steam  as  indicated  in 
figure  9,  where  the  barrel  contains  water  heated  by  a  steam  jet. 


Fig.  9. — Continuous  water  heated  aluminum  coil  used  at  University  Farm 
for  pasteurizing  grape  juice  into  barrels  or  kegs.  At  left,  complete  pasteurizer; 
at  right,  coil.     The  juice  to  be  sterilized  flows  through  the  coil. 


CIRC.  313]  FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES  11 

Ordinary  large  steam  jacketed  aluminum-walled  jelly  kettles  are 
very  commonly  used  as  pasteurizers  in  the  eastern  grape  growing 
districts  of  the  United  States- (fig.  10). 

The  same  objection  holds  with  the  open  kettle  as  was  the  case  with 
pasteurizing  in  the  open  barrel. 


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Fig.  10. — Battery  of  steam  jacketed  kettles  used  for  fruit  juices  and  jellies. 
(Courtesy,  Wearever  Aluminum  Company.) 

A  common  form  of  discontinuous  pasteurizer  consists  of  a  tank  or 
barrel  in  which  is  placed  an  aluminum  steam  coil  or  a  tin-coated 
copper  coil.  The  tank  is  filled  with  juice,  and  steam  admitted  to  the 
coil  heats  the  juice  to  the  pasteurizing  temperature.  This  pasteurizer 
is  objectionable  because  of  excessive  exposure  of  juice  to  the  air  with 
consequent  contamination  and  oxidation.  There  is  also  danger  of 
scorching  the  juice  which  is  in  immediate  contact  with  the  coils. 

Filters. — Some  fruit  juices  should  be  made  as  clear  as  possible 
before  bottling.     This  usually  involves  filtration. 

The  simplest  filter  is  the  bag  filter,  which  consists  of  a  conical 
heavy  duck  or  felt  bag  which  is  used  in  the  same  manner  as  an  ordi- 
nary jelly  bag  (fig.  11).  The  rate  and  effectiveness  of  filtration 
may  be  increased  by  the  addition  of  infusorial  earth  to  the  juice 


12 


UNIVERSITY    OP    CALIFORNIA EXPERIMENT    STATION 


before  filtration  as  described  later  under  filter  presses.  Bag  filters 
commonly  hold  ten  gallons  of  juice  at  each  filling.  They  are  satis- 
factory for  small  scale  operations.  -A  small  size  suction  filter  for 
home  use  has  been  placed  on  the  market.  It  is  very  suitable  for  small 
factories,  and  is  known  as  the  "Cellulo  filter"   (fig.  12). 


Fig.  11. — Felt  jelly  bag  for  preliminary  filtration. 

For  larger  scale  manufacture  of  fruit  juices  some  form  of  pulp 
filter  or  asbestos  fiber  filter  is  generally  used.  Pulp  filters  vary 
greatly  in  appearance  and  design.  Figure  13  illustrates  a  very 
effective  type.  It  consists  of  several  thick  disks  of  cotton  pulp  in  a 
tin-lined  copper  cylinder.  The  disks  of  pulp  are  separated  by  metal 
screens  and  the  juice  is  admitted  to  the  cylinder  in  such  a  way  that 
each  layer  of  pulp  acts  as  an  independent  filter,  thus  giving  a  very 
large  aggregate  filtering  surface.  The  pulp  is  washed  after  use  by 
stirring  in  water  with  a  mechanical  agitator.  It  is  then  pressed  into 
disks  and  used  again  in  the  filter.  A  filter  of  this  type  using  only 
two  disks  has  proved  satisfactory. 


ClRC.  313]  FRUIT    JUICES   AND   FRUIT    JUICE   BEVERAGES 


13 


Fig.  12. — "Cellule"  pulp  filter,  suitable  for  small  scale  filtration. 


Courtesy 
Karl  Kiefer  Mfg.  Co. 


Fig.  13. — Wood  pulp  fruit  juice  filter. 


14 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


The  Seitz  filter  consists  of  a  very  fine  tin  or  silver  screen  or  series 
of  screens,  enclosed  in  a  cylinder  or  cabinet  (fig.  14).  The  first  juice 
to  be  passed  through  the  filter  is  mixed  with  asbestos  fiber  of  a  special 
grade  manufactured  for  this  filter,  which  gathers  on  the  screen  form- 
ing a  filtering  surface.  The  use  of  the  special  fiber  in  this  filter 
"polishes"  the  juice,  giving  it  a  permanent  brilliancy. 


Fig.  14. — Filter  using  asbestos  fiber  as  a  filtering  medium. 
(Courtesy,  Donald  Robertson,  Pacific  Coast  agent,  Seitz  filters.) 


Filter  presses  are  used  in  many  industries  for  filtering  large 
volumes  of  various  liquids  and  have  also  been  used  successfully  for 
fruit  juices.  With  these,  filtration  is  accomplished  by  forcing  the 
liquid  under  heavy  pressure  through  cloth  or  canvas  sheets  held 
between  metal   or   wooden   plates.     "Filter-Cel"   or  other  form   of 


Circ.  313] 


FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES 


15 


infusorial  earth  is  added  to  the  liquid  to  be  filtered.  It  should  be 
washed  in  water  before  use  in  filtering  fruit  juices  to  avoid  the 
characteristic  earthy  taste.  "Super-Cel"  is  a  specially  prepared 
"Filter-Cel"  which  does  not  impart  this  objectionable  taste.  Metal 
parts  in  contact  with  the  juices  should  be  heavily  tinned  or  silver 
plated.  A  small  laboratory  size  filter  press  shown  in  figure  15  illus- 
trates the  working  parts  of  the  factory  size  filter  press  very  well. 


Fig.  15. — Small  filter  press  showing  filter  cloths  and  frames  in  position. 


Containers. — Grape  juice  is  usually  stored  several  months  at  a 
low  temperature  to  allow  the  excess  of  cream  of  tartar  to  separate 
and  to  aid  clarification.  Some  factories  use  50-gallon  barrels  for 
storage;  glass  carboys  (demijohns)  are  better  because  glass  does  not 
injure  the  flavor  of  the  juice. 

Glass  bottles  are  the  usual  final  containers  in  which  the  juices  are 
sold.  Two  types  are  in  use :  those  closed  with  an  ordinary  crown  or 
soda  water  bottle  caps  and  those  upon  which  the  Goldy  caps  are  used. 
The  Goldy  caps  may  be  removed  without  the  use  of  soda  bottle  opener. 
Both  styles  of  caps  are  applied  by  special  machines,  which  fasten  the 
caps  to  the  bottles  by  pressure.     See  figure  16. 

Cans  may  be  used  for  white  juices,  but  the  color  of  red  juices 
often  changes  to  blue  or  purple  in  tin  or  enamel  lined  tin  containers, 
Enamel  lined  tin  cans  also  often  impart  a  bitter  or  resinous  taste. 

Bottle  Pasteurizers. — Large  glass  carboys  used  for  storage  of 
juices  are  sterilized  by  means  of  live  steam  in  an  enclosed  box  into 
which  the  carboys  may  be  run  on  a  truck.  They  are  sterilized  in  this 
way  just  before  they  are  to  be  filled  with  hot  juice. 


16 


UNIVERSITY    OF    CALIFORNIA— EXPERIMENT    STATION 


Filled  bottles  or  cans  of  juice  are  sterilized  by  heating  them  in 
water  to  the  desired  temperature.  The  pasturizer  may  consist  of  a 
shallow  metal  or  wooden  vat  with  perforated  false  bottom  to  hold 
bottles  or  cans.  A  perforated  steam  coil  is  located  beneath  the  false 
bottom.  The  vat  is  filled  with  water  which  is  gradually  raised  to  the 
pasteurizing  temperature  and  held  for  the  required  time.  A  more 
elaborate  pasteurizer  of  the  cabinet  type  is  illustrated  in  figure  17. 


Fig.  16. — Foot-power  bottle  capping  machine  suitable  for  small  factories. 


The  bottles  are  heated  by  sprays  of  water  which  is  gradually  brought 
to  the  pasteurizing  temperature  by  heating  outside  the  pasteurizer, 
and  delivered  to  the  sprays  by  a  pump.  The  water  is  collected  and 
re-circulated  through  the  heater  and  pump. 

Steam  Supply. — A  steam  plant  will  be  necessary  except  for  the 
very  smallest  factories.  To  operate  a  pasteurizer  capable  of  steriliz- 
ing 500  gallons  of  juice  per  hour  a  25  horsepower  boiler  should  be 
available;  other  sizes  in  proportion  to  output.  Steam  is  also  neces- 
sary for  sterilizing  empty  barrels,  carboys,  pipe  lines,  press  cloths, 
etc.,  that  come  in  contact  with  the  juice;  but  if  the  boiler  is  large 


Circ.  313] 


FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES 


17 


enough  to  operate  the  pasteurizer,  it  will  also  furnish  enough  steam 
for  these  miscellaneous  purposes.  It  is  desirable  that  steam  and  an 
abundance  of  water  be  available  in  any  plant. 

Bottle  Filling  Machines. — In  the  production  of  bottled  juices  in 
quantity  some  form  of  automatic  bottle  filler  will  be  needed  (fig.  18). 
Those  formerly  used  in  breweries  answer  the  purpose  very  well. 
For  the  small  factory  a  soft  half -inch  hose  and  a  small  hand  bottle 
filling  device  may  be  used. 


Fig.  17. — Cabinet  form  of  bottled  juice  pasteurizer. 
(Courtesy,  Hydraulic  Press  Mfg.  Co.) 


Labeling  Machines. — Bottles  or  cans  may  be  labeled  by  special 
machines  much  more  rapidly  and  just  as  neatly  as  by  hand.  Such 
a  machine  is  almost  a  necessity  for  large  plants,  but  is  not  needed 
in  small  plants. 

Equipment  for  Home  Manufacture  of  Juices. — Small  combination 
fruit  crushers  and  presses  for  use  in  the  kitchen  may  be  bought 
through  any  hardware  store.  Grapes  and  berries  may  be  crushed 
with  a  potato  masher,  or  by  the  hands,  and  pressed  in  a  small  meat 
press.  An  ordinary  jelly  bag  made  of  muslin  or  flannel  will  serve 
for  a  filter.  A  wash  boiler  fitted-  with  a  false  bottom  may  be  used 
as  a  pasteurizer. 


18  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


Fig.  18. — Bottling  machine  for  fruit  juice. 


ClRC.  313  J  FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES  19 


GRAPE    JUICE    MANUFACTURE 

Qualities  Desired  in  Grape  Juice. — A  red  juice  is  commonly  pre- 
ferred, and  the  more  intense  the  color  the  better.  High  acidity,  that 
is,  a  tart  flavor,  is  necessary  in  a  successful  product.  Clearness  is 
desirable,  but  not  essential,  although  a  heavy  deposit  of  pulp  detracts 
from  the  appearance  of  the  bottled  product.  A  slight  cloudiness  is 
not  objectionable  when  the  juice  is  put  up  in  cans. 

In  adidtion  to  these  qualities  the  juice  must  have  a  distinctive  and 
pleasing  flavor.  If  the  product  is  to  become  popular  this  flavor  must 
be  very  pronounced. 

Varieties  of  Grapes  for  Juice. — At  present  the  most  popular  juices 
are  those  made  from  the  Concord  and  other  closely  related  eastern 
(i.e.,  Labrusca)  varieties.  In  California  the  Pierce  Isabella  is  used 
as  a  substitute  for  the  Concord,  as  it  combines  in  a  single  variety 
high  color,  high  acid,  and  the  favored  flavor  of  the  Fox  grape 
varieties.    It  may  be  grown  most  successfully  in  the  coast  counties. 

None  of  the  commonly  grown  Calif ornian  (European)  varieties 
possess  in  a  single  variety  all  of  the  desired  qualities.  The  Muscat 
has  a  strong  flavor  but  is  white  in  color  and  not  very  high  in  acid. 
When  blended  with  suitable  varieties  of  red  wine  grape  juices  a  very 
excellent  product,  which  compares  favorably  with  Concord  juice  in 
color,  acid,  and  flavor,  can  be  made.  It  is  believed  that  such  a  juice 
can  become  a  strong  competitor  of  eastern  juices.  The  better  varie- 
ties of  red  wine  grapes  such  as  Barbera,  Valdepenas,  St.  Macaire  and 
Crabbe's  Black  Burgundy,  give  better  results  than  do  the  commoner 
varieties,  such  as  Petite  Sirah,  Zinfandel,  Alicante  Bouschet,  Carig- 
nane,  and  others,  but  these  latter  varieties  also  may  be  used  success- 
fully to  blend  with  Muscat  juice. 

For  the  production  of  juices  of  delicate  flavor,  which  will  appeal 
to  connoisseurs  of  fine  wines,  varieties  such  as  Semillon,  Franken 
Riesling,  or  Colombar  should  be  blended  with  acid  varieties,  such  as 
Burger  or  West's  White  Prolific. 

Gathering  the  Grapes. — The  composition  of  the  finished  juice  is 
governed  by  the  time  of  picking  the  grapes.  Eastern  varieties  should 
be  gathered  at  about  17°  to  18°  Balling  as  indicated  by  the  Balling 
" sugar"  tester  shown  in  figure  19.  This  concentration  is  easily 
reached  in  California,  but  is  difficult  to  obtain  in  eastern  grape 
growing  regions. 


20  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

Muscat,  Semillon,  and  other  flavor  grapes  must  reach  the  stage 
of  maturity  at  which  their  flavor  is  well  developed.  This  is  22°  to 
23°  Balling.  The  acid  grapes  to  be  blended  with  the  flavor  grapes 
should  have  a  good  color  but  still  be  very  sour;  that  is,  about  18° 
Balling.  With  Zinfandel  grapes,  in  order  to  obtain  both  acid  and 
color,  it  will  be  necessary  to  gather  the  first  crop  at  20°  Balling  for 
color  and  at  the  same  time  enough  of  the  second  crop  to  impart  a  very 
tart  flavor.  Ordinarily  the  color  and  the  acid  varieties  will  have  to 
be  gathered  several  weeks  before  the  flavor  varieties  have  ripened 
sufficiently  and  their  juice  preserved  and  stored  until  it  is  to  be 
blended  with  the  flavor  juice  later. 

A  test  of  the  acidity  of  the  grapes  is  important.  The  finished  juice 
should  contain  from  .9  to  1.1  per  cent  acid  expressed  as  tartaric  acid. 
This  test  is  simple  and  can  be  made  with  equipment  and  solutions 
which  may  be  obtained  from  any  chemical  supply  house.  Names  of 
these  companies  will  be  furnished  upon  request  to  Division  of  Viti- 
culture and  Fruit  Products,  University  of  California, 

To  make  the  test,  measure  10  cubic  centimeters  of  the  juice  by 
means  of  a  10  cc  pipette  into  a  tumbler.  Add  water  to  fill  the  tumbler 
one-quarter  full.  Add  a  few  drops  of  phenolphthalein  indicator  solu- 
tion. Fill  a  burette  with  tenth  normal  (N/10)  sodium  hydroxide  solu- 
tion and  read  the  level  of  the  liquid  in  the  burette.  Add  the  tenth 
normal  sodium  hydroxide  solution  slowly  to  the  juice  in  the  tumbler 
until  a  drop  finally  turns  the  liquid  in  the  tumbler  permanently  pink. 
Read  the  level  of  the  liquid  in  the  burette  again.  The  difference 
between  the  first  and  second  readings  represents  the  amount  of  solu- 
tion needed  to  neutralize  the  acid  of  the  juice.  This  figure  multi- 
plied by  0.075  will  give  the  acidity  of  the  juice  in  per  cent.  Example : 
first  reading,  4.0 ;  second  reading,  15.5.  Difference  11.5.  Acidity  = 
11.5  X  .075  ==  .86  per  cent. 

The  grapes  should  be  crushed  as  soon  after  picking  as  possible  to 
forestall  molding  or  souring.     Only  clean  lug  boxes  should  be  used. 

Crushing  and  Stemming. — The  grapes  must  be  thoroughly  crushed. 
White  grapes  should  not  be  stemmed  because  the  stems  aid  in  press- 
ing. Red  wine  grapes  should  be  stemmed  for  the  reason  that  heating 
the  juice  later  to  extract  the  color  will  leach  from  the  stems  an 
astringent  principle  of  disagreeable  flavor. 

Pressing. — White  grapes  must  be  as  completely  pressed  as  possible 
without  heating.  The  color  of  grapes  used  for  red  juice  is  held  in  the 
skins  and  this  must  be  extracted  by  heat.  Therefore,  such  grapes 
are  not  finally  pressed  until  the  juice  has  been  heated  in  contact 
with  the  skins. 


ClRC.  313]  FRUIT    JUICES   AND   FRUIT    JUICE   BEVERAGES  21 

Extraction  of  Color. — There  are  two  methods  in  use  for  extraction 
of  color.  The  most  commonly  used  process  consists  of  heating  the 
mixed  skins  and  juice  in  a  large  double  jacketed  steam-heated 
aluminum  kettle  to  160°  F  for  a  few  minutes.  The  grapes  are  then 
pressed  hot  at  once. 


Fig.  19. — Balling  hydrometer,  hydrometer  cylinder  and  thermometer  for 
testing  sugar  content  of  juice. 

The  other  method  consists  in  first  lightly  pressing  the  crushed 
stemmed  grapes  to  obtain  one-half  or  two-thirds  of  the  juice.  The 
pomace  (pressed  skins  and  seeds)  is  thrown  into  a  clean  wooden  vat. 
The  juice  is  heated  in  one  of  the  bulk  pasteurizers  previously 
described,  to  about  140°  F  and  is  then  mixed  with  the  pomace  and 
allowed  to  stand  until  sufficient  color  is  extracted.  This  will  be  four 
to  eight  hours.  The  skins  and  juice  should  be  frequently  stirred  to 
hasten  color  extraction.  The  grapes  may  then  be  pressed.  Heating 
destroys  the  slimy  character  of  the  crushed  grapes  and  thus  facilitates 
pressing  so  that  the  presence  of  the  stems  is  not  necessary. 


22  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

The  second  method  described  above  for  color  extraction  has  given 
the  better  results  since  overheating  is  avoided.  High  temperatures 
(150°  F  to  180°  F)  of  mixed  juice  and  skins  cause  the  juice  to 
develop  a  harsh  flavor,  probably  because  of  materials  extracted  from 
the  seeds.  It  has  been  found  that  temperatures  for  mixed  skins  and 
juice  of  130°  F  to  140°  F  give  the  best  flavor  and  at  the  same  time 
permit  of  satisfactory  extraction  of  color. 

First  Pasteurization. — The  juice  must  be  heated  to  coagulate  pro- 
teins, which  would  cause  the  juice  to  be  cloudy  if  bottled  direct  from 
the  press.  This  is  done  by  heating  the  juice  to  a  temperature  equal 
to  or  greater  than  the  final  pasteurizing  temperature,  otherwise  the 
second  heating  would  cause  the  juice  to  again  become  cloudy  by  the 
further  precipitation  of  proteins,  If  crystallization  of  cream  of 
tartar  in  the  bottled  product  is  to  be  prevented,  the  juice  must  be 
stored  several  months  to  permit  this  to  separate  before  final  bottling ; 
and  in  order  that  the  juice  will  not  ferment  during  this  storage  it 
must  be  sterilized  in  or  into  sealed  containers. 

In  some  grape  juice  factories  the  juice  is  heated  to  a  temperature 
of  175°  to  190°  F  in  aluminum  kettles  and  then  transferred  at  this 
temperature  to  glass  carboys  that  are  still  hot  from  having  been  steril- 
ized in  steam.  Any  one  of  the  continuous  pasteurizers  previously 
described  may  also  be  used.  The  carboys  in  either  case  are  filled  to 
overflowing  and  are  then  sealed  with  corks  sterilized  in  scalding  hot 
melted  paraffin.  The  tops  of  the  carboys  and  corks  are  then  sealed 
with  paraffin  or  wax. 

In  California  25-  or  50-gallon  oak  barrels  are  often  used  instead 
of  glass  containers.  The  barrels  must  be  sound  and  sweet.  New 
barrels  should  first  be  treated  with  hot  soda  ash  solution  and  several 
days'  leaching  with  hot  water  to  remove  the  oak  flavor.  Just  before 
they  are  to  be  filled,  the  barrels  are  thoroughly  steamed  and  the  hot 
juice  is  filled  into  them.  They  are  bunged  tightly  with  ordinary  ship- 
ping bungs  and  muslin.  Both  the  bungs  and  muslin  must  be  sterilized 
several  minutes  in  boiling  water  before  use.  After  filling  and  bung- 
ing, the  barrels  should  be  rolled  slightly  on  their  sides  to  permit  the 
hot  juice  to  further  sterilize  the  bungs.  The  outside  of  the  barrels 
should  be  thoroughly  painted  with  melted  paraffin  or  shellac  to  render 
the  wood  airtight.  Barrels  have  been  proved  by  repeated  tests  to 
be  very  much  inferior  to  glass  containers  for  storage  because  the 
materials  extracted  from  the  wood  injure  the  flavor  of  the  juice  and 
permit  browning  through  oxidation.  Their  use  is  not  recommended 
if  large  glass  carboys  are  obtainable. 


ClRC.  313]  FRUIT    JUICES   AND   FRUIT    JUICE   BEVERAGES  23 

Reclaiming  Barrels. — Barrels  which  have  become  contaminated 
with  oil,  creosote,  fish  or  other  odoriferous  substances  can  not  be 
cleansed  sufficiently  to  make  them  suitable  for  the  handling  of  fruit 
juice.  The  delicate  nature  of  fruit  juices  is  such  that  a  slight  taint 
from  such  substances  renders  them  unpalatable.  Most  barrels  which 
have  been  used  for  fruit  juice,  syrups  or  concentrates,  soda  fountain 
syrups  and  vinegar  can  be  reclaimed  provided  proper  precautions 
are  taken. 

The  following  treatment  has  been  found  effective  in  cleansing 
barrels.  Wash  thoroughly  by  boiling  with  a  weak  lye  solution.  This 
can  be  done  by  filling  the  barrel  with  the  lye  solution  or  by  making  up 
the  solution  in  the  barrel  itself;  use  about  %  ounce  of  flake  caustic 
per  gallon  of  water  and  run  in  a  jet  of  live  steam  causing  the  solution 
to  boil  or  remain  near  boiling  for  one-half  to  three-quarters  of  an 
hour.  The  effectiveness  of  this  treatment  can  be  increased  by  allow- 
ing the  solution  to  remain  in  the  barrel  as  long  as  time  will  permit, 
for  example  overnight.  Then  wash  in  a  similar  manner  with  fresh 
water  to  remove  as  much  of  the  lye  as  possible.  Soda  ash  may  be 
used  instead  of  lye.  It  has  the  advantage  of  not  dissolving  the 
wood  fiber. 

Follow  this  by  soaking  with  a  weak  solution  of  hydrochloric,  citric 
or  tartaric  acid  to  remove  or  neutralize  the  remaining  lye.  Then 
wash  again  with  fresh  water  as  before  and  dry.  If  compressed  air  is 
available,  drying  can  be  accomplished  quickly  and  effectively  by  its 
use.  Otherwise  a  final  steaming  to  heat  the  barrel  thoroughly  will 
hasten  drying.  If  climatic  conditions  are  favorable  this  drying  can 
be  done  in  the  sun. 

Paraffining  Inside  of  Barrels. — When  the  inside  of  the  barrel  is 
thoroughly  dry,  and  not  until  then,  the  paraffin  can  be  applied. 
JTor  a  50-gallon  barrel  melt  3  or  4  pounds  of  paraffin.  It  will  not 
require  this  entire  amount  to  coat  the  barrel  but  an  excess  is  neces- 
sary to  insure  a  thorough  coating.  Heat  the  paraffin  until  it  is  smok- 
ing hot.  Have  only  one  bung  hole  open,  preferably  midway  in  the 
side  of  the  barrel.  Pour  the  hot  paraffin  into  the  barrel  using  a 
funnel.  Provide  for  escape  of  air  from  the  barrel  around  the  funnel 
otherwise  a  dangerous  spattering  of  the  molten  paraffin  will  occur. 
Place  the  bung  in  tightly  and  rock  the  barrel  vigorously  from  end 
to  end  at  the  same  time  rolling  it  slowly  until  it  has  been  rolled  com- 
pletely over  thus  permitting  the  paraffin  to  cover  the  sides  completely. 

Then  turn  the  barrel  on  end  and  agitate  it  in  such  a  way  as  to 
spread  the  paraffin  over  the  head.     Invert  the  barrel  and  repeat  the 


24  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

movement  to  cover  the  other  head.  Remove  the  bung  and  pour  out 
the  excess  of  molten  paraffin,  which  can  be  returned  to  the  heater  to 
be  used  in  the  next  barrel. 

The  amount  of  paraffin  required  for  a  barrel  will  be  determined 
by  the  thickness  of  the  coating,  which  is  determined  by  the  tempera- 
ture of  the  barrel,  of  the  molten  paraffin  and  the  speed  of  manipula- 
tion. A  thin  coat  of  paraffin  for  the  inside  is  as  effective  as  a  thick 
coat  and  more  economical. 

The  operation  can  be  facilitated  by  the  use  of  a  spray  machine 
designed  for  the  purpose.  If  a  large  number  of  barrels  are  to  be 
paraffined  the  initial  cost  of  the  spray  machine  would  be  offset  by  the 
saving  in  material. 

Barrels  treated  in  this  manner,  either  spruce  or  oak,  can  be  used 
to  store  juice  in  cold  storage  or  for  juice  preserved  by  the  addition 
of  chemical  preservatives.  Hot  juice,  however,  will  melt  the  paraffin 
and  defeat  the  purpose  for  which  the  barrels  were  prepared. 

Storage. — Separation  of  cream  of  tartar  is  greatly  hastened  by 
low  temperatures.  Therefore  large  factories  use  refrigeration  during 
storage.  When  refrigeration  is  not  available  the  same  results  are 
obtained  by  simply  storing  the  juice  through  the  winter  until  Febru- 
ary or  March  in  a  room  which  reaches  outside  winter  temperatures. 
Tests  show  that  storage  until  February  15  is  sufficient.  By  leaving 
the  doors  open  on  cold  nights  and  closed  during  the  day,  the  desired 
temperatures  will  be  readily  attained. 

The  containers  should  be  on  shelves  or  racks  well  above  the  floor 
in  order  that  the  juice  may  be  drawn  off  after  storage. 

Drawing  off  after  Storage. — The  settled  juice  after  storage  must 
be  racked,  that  is,  drawn  off  the  sediment.  This  is  most  conveniently 
done  by  siphoning.  A  half -inch  soft  rubber  hose  attached  to  a  short 
gooseneck  of  three-eighths  inch  tinned  copper  or  brass  pipe  makes 
a  convenient  siphon.  The  gooseneck  rests  on  the  bottom  of  the  carboy 
or  tank,  the  inlet  being  slightly  above  the  level  of  the  sediment  in  the 
container.  Thus  the  juice  is  drawn  downward  into  the  siphon  and 
the  sediment  is  not  disturbed.  The  juice  may  be  drawn  off  by  means 
of  a  plain  hose  without  use  of  gooseneck  if  care  is  exercised.  A  piece 
of  bent  half-inch  glass  tubing  about  three  feet  long,  attached  to  a 
hose  makes  a  convenient  racking  siphon. 

Filtration. — Some  grape  juice  manufacturers  merely  strain  the 
juice  from  the  storage  containers  through  cloth.  A  much  clearer 
product  may  be  obtained  by  filtering  through  one  of  the  filters  pre- 
viously described.  If  the  racking  of  the  juice  after  storage  has  been 
well  done,  filtration  is  rapid. 


ClRC.  313]  FRUIT    JUICES   AND   FRUIT    JUICE   BEVERAGES  25 

Bottling. — After  removal  of  cream  of  tartar  and  after  the  juice 
is  made  clear  as  described  above,  it  is  filled  into  bottles.  Quart  bottles 
must  be  filled  to  within  only  about  one  and  a  half  inches  of  the  top, 
this  space  being  necessary  for  expansion  of  the  juice  during  pasteuriz- 
ing". An  automatic  bottle  filling  machine  will  hasten  this  work.  The 
bottles  must  be  thoroughly  washed  before  use  and  should,  if  facilities 
permit,  be  sterilized  in  live  steam  a  short  time  before  filling,  but 
must  be  cool  at  time  of  filling  to  avoid  breaking. 

The  caps  used  in  sealing  the  bottles  should  be  placed  in  live  steam 
or  boiling  water  for  a  period  of  about  one  minute  just  before  use. 
This  will  destroy  mold  spores  on  and  in  the  cork  of  the  bottle  cap. 
Nearly  all  spoiling  of  juice  in  bottles  by  mold  growth  is  caused  by 
the  resistant  mold  spores  to  be  found  on  all  such  non-sterilized  caps. 
The  cork  is  a  poor  conductor  of  heat  and  thus  protects  the  spores 
during  sterilization  of  the  juice ;  hence  the  need  of  sterilizing  the 
corks  or  caps  before  use. 

Pasteurizing  Bottled  Juice. — The  bottled  juice  must  be  sterilized 
at  once  by  heat  to  prevent  spoiling.  A  temperature  of  165°  to  170°  F 
for  thirty  minutes  in  the  bottles  is  necessary  to  insure  complete  steril- 
ization of  juice  which  is  not  carbonated.  The  bottles  are  placed  in 
a  horizontal  position  on  the  false  bottom  of  the  sterilizer  in  order  that 
the  juice  shall  be  in  contact  with  the  cap  and  thus  make  certain  that 
the  inner  cork  disk  of  the  cap  reaches  the  sterilizing  temperature  of 
the  juice.  If  the  bottle  is  in  an  upright  position  the  air  space  in  the 
top  of  the  bottle  acts  as  an  insulator  and  prevents  the  cap  being 
thoroughly  heated.  The  bottles  are  covered  with  water  and  the 
water  heated  by  steam  or  direct  heat  to  between  170°  and  172°  F 
and  kept  at  this  temperature  30  minutes.  Tests  have  shown  that  there 
will  be  about  2°  difference  between  the  temperatures  of  the  bottled 
juice  and  the  surrounding  water.  Cooling  after  pasteurization  may 
be  hastened  by  gradually  cooling  the  bath  by  slowly  running  in 
cold  water. 

The  water  is  than  drawn  from  the  pasteurizer  and  the  bottles 
placed  in  a  room  free  from  violent  drafts  of  cool  air;  or  may,  if 
desired,  be  allowed  to  cool  in  the  pasteurizer.  The  latter  practice 
avoids  the  necessity  of  handling  the  hot  bottles.  Another  type  of 
pasteurizer  is  shown  in  figure  17.  In  this  pasteurizer  the  bottles  of 
juice  are  heated  by  sprays  of  hot  water. 

Storing  Bottled  Juice. — The  finished  juice  should  be  held  for  at 
least  four  weeks  at  a  warm  room  temperature  to  determine  whether 
it  will  remain  clear  and  free  from  mold. 


26  UNIVERSITY    OP    CALIFORNIA EXPERIMENT    STATION 

Bottling  Juice  Without  Removal  of  Cream  of  Tartar. — The  juice 
may  be  bottled  twenty-four  hours  after  crushing  of  the  grapes  if 
bottled  without  storage  to  remove  cream  of  tartar.  The  juice  may  be 
made  clear  by  processes  already  described ;  may  then  be  bottled  and 
pasteurized,  the  total  length  of  time  from  vine  to  bottle  not  exceeding 
three  days.  Such  juice  will,  however,  develop  a  crystalline  deposit  of 
cream  of  tartar.  This  does  not  affect  the  flavor,  and  injures  the 
juice  in  no  way,  except  in  appearance.  The  deposit  is  small,  but 
might  cause  the  consumer  to  doubt  the  purity  of  the  juice  unless  the 
label  were  designed  to  explain  the  presence  and  character  of  the 
crystals. 

This  method  reduces  the  expense  of  manufacture  and  the  invest- 
ment in  equipment.  Juice  so  made  is  handled  fewer  times  than  that 
made  by  the  usual  methods  and  is  therefore  richer  in  flavor  and  of 
better  color. 

Carbonating  Grape  Juice. — Carbonated  juices  are  always  more 
popular  than  still  juices  for  the  same  reason  that  sharp  or  sparkling 
cider  is  preferred  to  the  juice  fresh  from  the  apple.  Besides  increas- 
ing the  palatability  of  the  juice,  the  carbonating  greatly  reduces  the 
temperature  necessary  for  sterilization.  Juices  that  are  lightly 
carbonated  may  be  sterilized  at  150°  F  or  less. 

A  carbonated  juice  should  be  clear  and  free  from  sediment  in 
order  to  be  attractive. 

Carbonating  consists  in  impregnating  the  juice  with  carbonic  acid 
gas  and  in  bottling  under  a  pressure  of  the  same  gas.  Carbon  dioxide, 
that  is,  carbonic  acid  gas,  is  sold  in  the  liquified  state  in  steel 
cylinders. 

The  solubility  of  the  gas  in  the  juice  is  greatly  increased  by  low 
temperatures.  A  convenient  and  effective  system  of  carbonating  con- 
sists in  chilling  the  juice  to  near  freezing  and  in  agitating  the  chilled 
juice  in  a  strong,  sealed  container  into  which  the  gas  is  admitted 
under  pressure.  Fair  results  can  be  obtained  by  carbonating  the 
chilled  juice  in  open  containers.  Pressure  gauges,  safety  valves,  and 
automatic  pressure  controls  should  be  used  to  avoid  accidents  from 
bursting  of  the  container  by  excessive  pressures.  Fifteen  to  twenty 
pounds  pressure  per  square  inch  will  be  sufficient.  The  juice  after 
carbonating  is  filled  directly  into  bottles  and  capped  at  once. 

Another  system  of  carbonating  consists  in  impregnating  the  juice 
by  aspiration ;  that  is,  the  chilled  juice  is  passed  downward  through 
a  cylinder  filled  with  glass  or  porcelain  beads.  The  carbonic  acid  gas 
is  admitted  at  the  bottom  of  the  upright  cylinder.    The  gas  is  absorbed 


Circ.  313] 


FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES 


27 


by  the  stream  of  juice.  The  whole  apparatus  is  under  a  pressure  of 
carbon  dioxide.  The  juice  flows  directly  into  the  bottles  under 
pressure. 

A  convenient  and  simple  method  for  small  scale  operations  is  to 
place  the  juice  in  a  heavy  beer  keg";  connect  a  cylinder  of  gas  to  a 
carbonating  inlet  which  may  be  purchased  for  such  barrels;  admit 
gas  up  to  fifteen  pounds  pressure  and  agitate  and  roll  the  barrel  for 
about  fifteen  minutes,  admitting  gas  frequently  to  maintain  the 
pressure  at  fifteen  pounds.  If  the  juice  is  cool,  it  may  then  be  drawn 
off  and  bottled,  but  it  will  be  necessary  to  admit  gas  to  the  barrel 
occasionally  during  filling  of  the  bottles  to  maintain  a  constant 
pressure  (fig.  20). 


Fig.  20. — Simple  device  for  carbonating  fruit  juice  for  small  scale  production. 

The  bottles  of  carbonated  juice  are  sealed  and  sterilized  at  150°  F 
for  thirty  minutes.  The  bottles  should  not  be  handled  while  they  are 
still  hot  because  they  will  be  under  a  dangerous  pressure  owing  to 
expansion  of  the  gas  from  heat. 

Canning  Grape  Juice. — The  time  and  expense  of  manufacture  are 
greatly  reduced  if  the  juice  is  canned.  Red  juice  tends  to  become 
blue  or  purple  in  color  after  canning,  unless  heavily  lacquered  cans 
are  used.  For  this  reason  white  juice  has  been  more  satisfactory 
than  red  juice  for  canning.  Lacquered  cans  impart  a  disagreeable 
flavor. 


28  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

The  canning  of  white  juice  may  well  become  an  important  industry 
for  fruit  canneries.  A  process  suitable  for  commercial  use  is  as 
follows:  The  grapes  are  crushed  and  pressed.  The  juice  may  be 
heated  to  170°  F  and  allowed  to  stand  overnight  to  cool  and  settle, 
or  may  be  passed  at  once  through  cooling  coils  after  heating.  The 
cool  juice  may  be  filtered  roughly  and  filled  into  cans.  A  can  syrup- 
ing  machine  would  make  an  excellent  filling  device.  The  filled  cans 
may  be  passed  through  a  cannery  exhaust  box  slowly  and  heated 
therein  to  175°  F.  The  cans  of  hot  juice  may  be  capped  at  once  and 
turned  upside  down  to  cool.  Red  juice  may  be  canned  in  a  similar 
manner  but  is  not  so  satisfactory  as  the  white. 

A  modified  process  consists  in  warming  the  filtered  juice  to  about 
160°  F  for  10  minutes  to  expel  dissolved  air,  then  filling  into  cans, 
sealing,  and  sterilizing  in  water  at  175°  F  for  25  miuntes.  Unless 
air  is  expelled  from  the  juice  before  the  cans  are  sealed,  the  juice 
will  cause  corrosion  and  perforation  of  the  cans. 

Another  process  in  use  for  grape  juice  consists  in  heating  the 
filtered  juice  to  175°  F  and  filling  into  cans  at  this  temperature  and 
sealing  without  further  treatment.  Red  grape  juice  has  been  canned 
experimentally  by  heating  the  crushed  grapes  to  160°  F,  pressing, 
filtering  and  canning  in  enamel  lined  cans  as  directed  above. 

Since  less  attention  is  given  to  clarification  and  containers  are 
cheaper,  canned  juice  may  be  produced  with  less  expense.  It  should 
be  possible  to  sell  it  for  30  cents  or  less  per  quart  can  at  retail  if 
grapes  may  be  had  at  $40  a  ton  or  less,  At  $40  a  ton  for  grapes  the 
raw  material  for  one  quart  of  juice  costs  6%  cents.  .  The  can  and 
label  will  cost  about  4  cents,  the  cost  of  manufacture  not  more  than 
2  cents  and  the  case  about  2  cents  a  quart.  This  gives  a  total  cost  of 
about  14^  cents  a  quart. 

Pasteurizing  Juice  in  Barrels. — Either  red  or  white  juice  may  be 
pasteurized  into  sterilized  barrels  as  described  elsewhere,  at  175°  F. 
The  barrels  must  be  bunged  at  once  with  sterilized  bungs  and  the  out- 
side of  the  barrels  coated  with  paraffin,  shellac  or  other  impervious 
coating  to  prevent  infection.  Such  juice  may  be  exported  to  foreign 
countries  for  various  purposes  or  sold  in  the  United  States  for  use  in 
large  soft  drink  dispensaries  or  at  picnics,  etc.,  where  an  inexpensive 
juice  of  good  quality  is  desired.  Some  juice  factories  store  juice  in 
bulk  in  this  manner  to  permit  settling  before  filtration  and  bottling. 

Preservation  of  Juice  with  Sulfurous  Acid. — If  grape  juice  is 
stored  in  a  cool  place  (60°  F  to  65°  F  or  less),  it  may  be  kept  for  at 
least  one  year  by  the  addition  of  one-tenth  of  1  per  cent  sulfurous 
acid,  which  corresponds  to  12%  ounces  of  sulfurous  acid;  or  about 


ClRC.  313]  FRUIT    JUICES   AND   FRUIT    JUICE   BEVERAGES  29 

1%  gallons  of  commercial  6  per  cent  sulfurous  acid  solution  to 
100  gallons  of  juice.  Juice  stored  at  higher  temperatures  requires 
proportionally  larger  amounts  of  the  sulfurous  acid  to  prevent 
fermentation. 

Juice  preserved  in  this  way  cannot  be  used  for  drinking  purposes 
until  the  sulfurous  acid  is  removed.  This  can  be  done  by  heating  the 
juice  to  160°  F,  and  at  the  same  time  passing  a  violent  stream  of 
air  through  it  for  about  an  hour  and  a  half.  A  better  method  of 
removing  the  sulfurous  acid  is  to  heat  to  boiling  in  a  vacuum  pan 
and  pass  a  current  of  steam  through  the  boiling  juice  for  30-40 
minutes.  This  removes  enough  of  the  sulfurous  acid  to  permit  the 
juice  to  be  used  for  drinking  purposes,  syrup  making,  or  vinegar 
manufacture ;  or  the  juice  after  removal  of  the  preservative  may  be 
sterilized  in  barrels.  J.  H.  Wheeler  of  St.  Helena,  the  California 
Grape  Products  Company  of  Ukiah  and  others  have  preserved  and 
successfully  treated  juice  in  this  way  on  a  commercial  scale  for 
several  seasons. 

This  method  of  preservation  makes  it  possible  to  utilize  the  storage 
tanks  of  wineries  to  good  advantage  and  for  a  grape  syrup  factory  to 
have  juice  on  hand  throughout  the  year  at  little  expense. 

Juice  preserved  with  sulfurous  acid  should  not  be  allowed  to 
come  in  contact  with  iron  or  copper;  only  aluminum,  tin  or  glass 
should  be  used.  A  wooden  vat  and  aluminum  steam  coil  may  be  used 
to  heat  the  juice  during  the  removal  of  the  preservative ;  or  a  large 
glass-lined  steam  jacketed  vat  of  the  type  used  for  concentrating 
tomato  products  is  excellent.  An  air  compressor  of  rather  large 
capacity  is  also  necessary.  This  should  be  connected  to  an  aluminum 
or  block  tin  pipe  leading  to  the  bottom  of  the  heating  vessel,  or  a  piece 
of  steam  hose  may  be  used  to  deliver  the  air. 

Red  juice  when  preserved  with  sulfurous  acid  becomes  almost 
white  in  color,  but  when  the  sulfurous  acid  is  removed  most  of  the 
color  returns. 

Aeration  does  not  remove  all  of  the  sulfurous  acid  and  if  such 
juice  is  offered  for  sale  it  must  bear  the  statement  that  it  contains 
sulfurous  acid. 

Home  Methods  of  Grape  Juice  Making. — A  red  juice  is  more  satis- 
factorily made  in  the  kitchen  than  a  white  juice.  The  grapes  should 
not  be  too  ripe  but  should  be  still  rather  tart  when  picked.  A  mix- 
ture of  Muscat  and  red  wine  grapes  gives  a  very  satisfactory  juice. 

Crush  the  grapes  in  a  small  household  size  crusher  or  merely 
crush  them  with  the  hands  into  an  agateware,  tin,  or  aluminum  kettle. 


30 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


Heat  slowly  with  stirring  to  150°  F ;  a  dairy  thermometer  is  use- 
ful for  testing  the  temperature.  Set  aside  for  about  two  hours.  Place 
in  a  jelly  bag"  or  in  a  heavy  cloth  in  a  small  press.  Allow  to  drain 
into  a  pan  and  press  the  skins  and  pulp. 


Fig.  21. — Small  hand-power  capper. 


Strain  through  a  cloth  or  felt  bag.  Fill  into  clean  scalded  bottles. 
Cork  bottles  with  corks  that  have  been  boiled  five  minutes  in  water. 
Tie  the  corks  down  w7ith  string.  Place  the  bottles  horizontally  on  a 
false  bottom  in  a  wash  boiler  or  large  kettle.  Fill  the  vessel  with 
water  and  heat  the  water  to  175°  F  for  thirty  minutes.  Remove  bottles 
and  seal  corks  with  melted  paraffin.  Crown  finish  bottles,  crown  caps 
and  a  small  hand-power  capping  machine  may  be  used.  See  figure  21, 
illustrating  this  capper. 


CIRC.  313]  FRUIT    JUICES    AND    FRUIT    JUICE   BEVERAGES  31 

The  strained  juice  prepared  as  directed  above  may  be  heated  to 
180°  F  and  poured  into  hot,  scalded  Mason  or  glass  top  jars.  Scalded 
rubbers  and  caps  are  then  put  in  place,  the  jars  sealed  and  turned 
upside  down  to  cool.  This  method  is  simple  and  effective.  Never 
heat  grape  juice  to  the  boiling  point. 

Costs  and  Returns  on  Grape  Juice. — Judging  from  the  results  of 
experiments  at  the  University  Farm  and  at  Berkeley  it  would  be 
possible  to  erect  a  small  grape  juice  plant  for  about  $1,000  exclusive 
of  barrels,  bottles,  or  other  juice  containers,  This  plant  would  have 
a  maximum  capacity  of  about  five  tons  of  grapes  a  day  or  about  one 
hundred  tons  in  a  season  of  twenty  days;  or  would  produce  15,000 
to  20,000  gallons  of  juice  in  a  season.  It  consists  of  a  shed ;  a  small 
continuous  pasteurizer  made  of  50  feet  of  five-eighths  inch  aluminum 
pipe  coiled  inside  a  50-gallon  barrel;  a  3-horsepower  boiler  (5-horse- 
power  is  better)  ;  a  cement  vat  5  feet  long  by  2%  feet  wide  by  2  feet 
deep  with  steam  coil  for  pasteurizing  bottled  juice ;  a  small  pulp 
filter;  a  foot-power  Crown  bottle  capper;  a  hand-power  grape 
crusher;  a  medium  size  hand-power  screw  basket  press  and  miscel- 
laneous utensils  such  as  fiber  tubs,  pails,  dippers,  hose,  etc.  To  this 
must  be  added  glass  carboys  for  15,000  gallons  of  juice,  60,000  quart 
bottles  or  their  equivalent  in  other  sizes;  caps,  labels  and  shipping 
boxes.     The  estimated  cost  per  quart  bottle  is  as  follows: 

Grapes  at  $40  per  ton  and  yield  of  600  quarts  per  ton  $0.0625 

Bottle  at  4y2   cents  0450 

Caps  at  30  cents  per  gross  0020 

Labels   at  $10   per  thousand   0100 

Cost  of  handling  at  16  cents  per  gallon  0400 

Cost  of  packing  for  shipment  0300 

Total   $0.1895 

Total  cost  per  quart,  about  19  cents,  allowing  no  charge  for 
interest  on  investment  or  depreciation. 


UNFERMENTED    APPLE    JUICE 

The  manufacture  of  apple  juice  has  become  an  important  industry 
in  the  Pacific  Northwest,  where  several  breweries  have  been  successful 
in  producing  a  high  class  unfermented  cider.  Several  very  success- 
ful factories  of  moderate  size  exist  in  California.  Very  large  quanti- 
ties of  cider  in  bulk  either  fresh  or  benzoated  are  consumed. 

Of  the  bottle  juices  the  carbonated  cider  is  most  in  demand  and 
must  be^brilliantly  clear. 


32 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


The  general  principles  of  preparation  are  similar  to  those  used 
in  making  grape  juice.  Apple  juice  is  more  easily  injured  in  flavor 
by  heat  than  is  grape  juice,  and  therefore  requires  greater  care. 

Varieties  of  Apples  Used. — Apples  of  sprightly  to  acid  flavor  are 
best,  provided  they  are  ripe  and  possess  a  full  apple  flavor.  Of  the 
commercially  grown  varieties  of  California,  the  Yellow  Newtown 
has  been  found  satisfactory.  The  Bellflower  is  of  poor  flavor.  The 
Gravenstein  is  of  fair  quality  for  juice  but  not  so  good  as  the  New- 
town. Northern  Spy,  Winesap,  and  other  varieties  of  sprightly  flavor 
are  excellent,  but  scarce  in  California.  Varieties  of  very  low  acid, 
such  as  the  Tolman  Sweet,  are  of  little  value  and  produce  juices 
which  are  difficult  to  sterilize.  Varieties  also  which  may  have  suffi- 
cient acid  but  which  are  of  poor  flavor  are  not  successful.  To  this 
class  would  belong  the  Bellflower  and  Ben  Davis. 

The  apples  should  be  mature  enough  to  possess  their  full  flavor, 
but  should  not  be  over-ripe,  because  of  the  decrease  in  acidity 
after  maturity  is  reached  and  because  juice  from  over-ripe  fruit  is 
"gummy"  and  very  difficult  to  filter. 

Only  clean,  sound  fruit  should  be  used.  This  usually  means  that 
the  fruit  should  be  carefully  sorted  and  washed  before  crushing.  See 
illustration  of  fruit  washer,  figure  1. 


TABLE  2 

Comparative   Qualities   of   Juice  from   Varieties   of   Commercially   Grown 

Apples  (After  Gore) 


Variety 


Yellow  Newtown  (syn.  Albemarle  Pippin) 

Ben  Davis 

Winesap 

Tolman  (syn.  Tolman  Sweet) 

Northern  Spy 

Baldwin 

Roxbury  (syn.  Roxbury  Russet) 


Source 
Waynesboro,  Va 

Waynesboro,  Va 

Waynesboro,  Va 

Halls  Corners,  N.  Y 
Halls  Corners,  N.  Y 

Halls  Corners,  N.  Y 

Halls  Corners,  N.  Y 


Quality  of  sterilized  juice 


Juice  very  palatable;  distinguished 
from  the  fresh  only  by  the  slight 
cooked  taste  and  a  little  bleaching 
or  lightening  of  color. 

Quite  unpalatable;  lacking  in  dis- 
tinctive apple  flavor. 

Very  palatable;  the  fruity  flavor 
somewhat  impaired  by  steriliza- 
tion; slight  bleaching  noticeable; 
very  little  cooked  taste. 

A  very  dark  colored,  thick  juice; 
very  sweet  and  insipid. 

Very  fine  in  flavor,  a  fine  rich  juice, 
showing  slight  bleaching  and 
hardly  detectable  cooked  flavor. 

High  in  quality,  very  palatable, 
slightly  bleached  and  with  slight 
cooked  flavor. 

A  heavy,  rich  juice,  very  palatable; 
slightly  bleached  and  with  very 
slight  cooked  flavor. 


Ciec.  313] 


FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES 


33 


Tables  2  and  3  give  the  comparative  qualities  and  composition  of 
juice  from  varieties  of  commercially  grown  apples. 

TABLE  3 

Composition  of  Unfermented  Apple  Juice  from  Different  Varieties  of 
Apples   (After  Gore) 


Variety 


Total 

solids 

Per  cent 


Acid  as 

malic 

Per  cent 


Reducing 

sugar 
Per  cent 


Total 

sugar 

Per  cent 


Yellow  Newtown  (syn.  Albemarle  Pippin) 

Ben  Davis 

Winesap 

Tolman  (syn.  Tolman  Sweet) 

Northern  Spy 

Baldwin 

Roxbury  (syn.  Roxbury  Russet) 


12.35 
12.05 
11  64 
15.63 
14.90 
14 .31 
16.86 


0.53 
0.48 
0.46 
0.13 
0.61 
0.63 
0.70 


15 

11 

86 

10 

06 

10 

92 

13 

52 

12 

33 

12 

46 

13 

Removal  of  Arsenical  Spray  Residue. — Until  recently  pure  food 
and  drug  authorities  did  not  insist  on  the  removal  of  arsenical  and 
lead  spray  materials  from  apples  to  be  used  for  cider. 

Recent  federal  regulations,  which  place  the  tolerance  of  lead 
arsenate  at  1/100  of  a  grain  to  a  pound  of  fruit  are  now  being  rigidly 
enforced  and  necessitate  changes  in  the  former  methods  of  washing 
apples.  Lead  arsenate  cannot  be  removed  sufficiently  with  water  to 
meet  the  requirements  of  the  law.  However,  its  removal  from  apples 
which  are  to  be  used  in  the  manufacture  of  cider  or  vinegar  is  a 
less  serious  problem  than  its  removal  from  fruit  which  is  to  be 
marketed  fresh,  because  stronger  washing  solutions  can  be  used  with 
more  vigorous  agitation  with  cider  apples. 

Two  methods  of  removing  of  spray  residues  are  as  follows : 

"■Dissolve  4  pounds  each  of  soda  ash  (Na2  C03)  and  common  salt 
(Nad)  in  12.5  gallons  of  water.  Maintain  the  temperature  at 
100°  F.  Pass  the  apples  through  this  solution  agitating  gently. 
Allow  fruit  to  remain  in  the  solution  at  least  5  minutes  but  not  more 
than  10  minutes.    Rinse  with  fresh  water."2 

Another  method  consists  in  washing  with  dilute  hydrochloric  acid. 
"Of  the  many  compounds  tested  none  has  proved  to  be  superior  to 
hydrochloric  acid.  When  used  at  concentrations  varying  between 
one-fourth  of  one  per  cent  and  two  per  cent  (actual  acid)  this  com- 
pound has  been  found  to  be  very  effective  in  the  removal  of  arsenical 

2  Headden,  W.  P.  Eemoval  of  arsenate  of  lead  from  sprayed  fruit.  Colo. 
Agr.  Exp.  Sta.  Press  Bui.  63:  1-4.     1926. 


34  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

residue  from  both  apples  and  pears,  Indications  are  that  this  acid 
will  prove  even  more  efficient  when  adequate  washing  devices  are 
perfected. '  '3 

Wiping  has  been  resorted  to  by  many  for  the  removal  of  spray 
residues.  The  expense  of  hand  wiping  is  excessive  and  is  not  prac- 
tical. Numerous  ingenious  devices  for  wiping  mechanically  have  been 
invented,  some  of  which  are  very  effective.  The  manufacturers  of 
fruit  handling  equipment  can  furnish  machines  especially  designed 
for  this  work. 

Crushing  and  Pressing. — Apple  tissue  is  firm  and  tough  and  the 
cells  possess  heavy  walls.  Consequently  crushing  must  be  thorough 
and  pressing  severe  to  obtain  a  high  yield  of  juice.  Crushing  too  fine, 
however,  causes  the  pulp  to  be  too  soft  to  press  without  danger  of 
breaking  the  press  clothes.  Pieces  ranging  in  size  from  one-eighth 
to  one-half  inch  in  diameter  are  satisfactory.  The  crusher  can  be 
set  to  grind  to  any  desired  degree  of  fineness. 

The  crushed  fruit  is  placed  in  heavy  coarse-weave  cloths  and  the 
fruit  is  enclosed  by  folding  the  cloth.  Each  cloth  of  fruit  is  placed 
between  racks  made  of  hardwood  slats.  Pressure  is  applied  usually 
by  a  hydraulic  pump.  A  pressure  of  at  least  500  pounds  per  square 
inch  is  necessary  for  the  best  results.  A  ton  of  apples  should  yield 
160  gallons  of  juice  if  well  pressed.  The  pomace,  that  is,  the  press 
cake,  will  yield  more  juice  if  broken  and  pressed  a  second  time,  this 
juice  being  preferably  used  for  vinegar.  By  using  a  pomace  picker  or 
crusher  (fig.  22)  the  yield  of  juice  may  thus  be  increased  greatly. 

Clearing  the  Juice. — A  common  method  of  clearing  the  juice 
consists  in  heating  to  precipitate  proteins  and  gums,  cooling  the 
heated  juice,  and  filtering  until  clear.  Methods  of  filtering  described 
for  grape  juice  can  be  used  for  apple  juice. 

One  of  the  most  successful  methods  consists  in  mixing  1-2  per  cent 
by  weight  of  refined  "Filter-Cel"  with  the  juice  and  filtering  in  a 
filter  press.  Two  or  more  nitrations  are  usually  necessary.  If  the 
juice  is  to  be  carbonated  before  bottling  it  needs  to  be  heated  to  from 
150°  to  155°  F  only;  but  if  to  be  bottled  without  carbonating  it  must 
be  heated  to  from  165°  to  170°  F.  In  other  words,  the  juice  is  heated 
before  filtration  to  a  temperature  equal  to  or  greater  than  that  to  be 
used  in  sterilizing  the  juice  in  the  final  bottles  because  if  it  is  heated 
to  a  lower  temperature  before  filtration  the  higher  temperature  during 
final   pasteurizing   may   cause   the   juice   to   become   cloudy   through 


3  Eobinson,  B.  H.,  and  Henry  Hartman.  A  progress  report  on  the  removal  of 
spray  residue  from  apples  and  pears.  Oregon  Agr.  Exp.  Sta.  Bui.  226:  7-46. 
1927. 


Circ.  313] 


FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES 


35 


further  precipitation  of  protein.  Some  factories  filter  the  fresh 
unpasteurized  unhealed  juice  and  bottle  without  the  preliminary 
pasteurizing  noted  above  using  only  the  final  pasteurizing.  This  can 
be  safely  done  with  juice  from  yellow  Newtown  apples. 

Aluminum,  tin,  glass,  silver  and  monel  metal  surfaces  may  be 
used  in  contact  with  hot  apple  juice  with  safety.  Most  other  metals 
are  acted  upon  b}^  the  acid  of  the  juice. 


Fig.  22. — Pomace  picker  or  crusher. 
(Courtesy,   Hydraulic   Press   Mfg.   Co.) 


Carbonating  Apple  Juice. — The  methods  described  for  carbonating 
grape  juice  are  also  suitable  for  apple  juice. 

If  carried  out  at  room  temperature  the  juice  should  be  carbonated 
to  about  15  pounds  pressure.  If  the  juice  is  first  chilled  to  32°-36°  F 
it  will  absorb  the  gas  more  readily  and  carbonating  to  5  pounds 
pressure  in  a  clean  barrel  will  be  sufficient ;  or  merely  slowly  passing 
the  gas  through  the  cold  juice  will  cause  it  to  absorb  enough  to 
impart  a  sharp  flavor  to  the  bottled  juice,  although  this  method  is 


36  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

wasteful  of  gas.     It  is  preferable  to  use  some  form  of  carbonating 
machine  designed  for  the  purpose. 

Apple  juice  is  greatly  improved  by  carbonating  and  all  such  juice 
for  sale  in  bottles  should  be  so  treated. 

Pasteurizing. — Carbonated  juice  may  be  sterilized  at  150°  F  for 
thirty  minutes.  If  the  juice  has  not  been  carbonated  it  should 
be  heated  to  170°  F  for  thirty  minutes.  Carbonating  checks  the 
development  of  mold  thereby  making  possible  a  lower  sterilization 
temperature. 

Spoiling  of  Apple  Juice  by  Mold. — Bottle  caps  are  the  usual  source 
of  infection.  Caps  are  readily  sterilized  before  use  by  immersing 
them  in  boiling  water  for  one  minute.  This  sterilization  will  greatly 
reduce  loss  from  mold  growth.  Bottles  should  also  be  sterilized  in 
steam  or  hot  water  before  use. 

Canned  Apple  Juice. — Apple  juice  retains  its  flavor  well  in  cans 
and  this  method  offers  the  cheapest  way  of  placing  the  juice  on  the 
market  in  small  containers  in  sterilized  form.  Unless  properly  canned, 
cider  will  attack  the  tin  plate  vigorously  with  the  formation  of 
hydrogen  gas,  and  swelling — or  even  perforation  of  the  cans. 

Canned  juice  need  not  be  perfectly  clear,  but  should  not  show 
a  heavy  deposit  in  the  can.  The  following  method  has  proved 
successful : 

The  fruit  is  crushed  and  pressed.  The  juice  is  then  filtered  through 
felt  filter  bags  or  heavy  duck  bags  to  remove  particles  of  pulp.  Place 
cold  juice  in  plain  tin  cans  (never  use  enamaled  cans)  and  heat  in 
a  steam  box,  that  is  in  live  steam,  until  the  juice  in  the  center  of 
the  can  reaches  180°  F.  Seal  immediately.  Be  certain  that  the  can 
is  completely  full  so  that  after  it  is  sealed  no  head  space  remains. 
Cans  which  are  not  completely  full  should  be  emptied  and  the  cider 
used  in  the  next  lot.  Sterilize  cans  at  175°  F  for  15  minutes.  Chill 
and  store  in  a  dry  place. 

After  cooling  the  juice  contracts  in  volume  leaving  a  head  space 
of  about  %  inch  in  depth. 

Another  method  in  use  under  commercial  conditions  is  the  fol- 
lowing: The  fresh  juice  from  the  press  is  strained  through  several 
layers  of  cheese  cloth ;  is  then  heated  to  180°  F  and  run  directly  into 
cans  which  are  filled  level  full.  The  cans  are  sealed  immediately  and 
no  further  heating  is  given.  Usually  such  juice  is  not  so  clear  as  that 
made  by  the  first  process  but  is  of  good  flavor. 


CIRC.  313]  FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES  37 


LOGANBERRY  JUICE 

Loganberry  juice  has  become  very  popular  during  the  past  few 
years  and  is  now  produced  on  a  large  industrial  scale  in  Oregon, 
making  the  growing  of  this  fruit  very  profitable.  The  development 
of  loganberry  juice  manufacture  is  largely  due  to  work  of  Professor 
C.  I.  Lewis,  formerly  of  the  Oregon  Agricultural  College.  The  juice 
is  of  deep  red  color,  very  rich  flavor,  and  high  acidity.  Thoroughly 
ripe  fruit  gives  the  best  juice,  that  from  under-ripe  berries  being 
light  in  color,  excessively  tart,  and  astringent  in  flavor. 

Extraction  of  Juice. — The  juice  is  best  extracted  by  a  combination 
of  crushing,  heating  and  pressing. 

The  berries  may  be  crushed  in  a  grape  crusher,  but  wooden  or 
tinned  rollers  should  be  used  because  the  acid  of  the  juice  attacks 
iron.  The  crushed  fruit  should  be  heated  in  tin-lined  or  glass-lined 
kettles,  with  constant  stirring,  to  about  140°  F  and  pressed  at  once. 
If  aluminum  kettles  are  used  care  should  be  taken  not  to  allow  juice 
to  stand  in  them  because  aluminum  is  rapidly  attacked  by  most  acid 
juices.  Long  continued  heating  extracts  tannin  and  disagreeable 
flavors  from  the  seeds.  The  rack  and  cloth  type  of  apple  press  should 
be  used  for  pressing. 

Clearing  the  Juice. — The  juice  should  be  cooled  after  pressing 
and  before  filtration.  Because  the  juice  is  rich  in  pectins  and  gums 
it  is  difficult  to  filter.  Several  filtrations  through  pulp  or  asbestos 
are  usually  necessary  to  render  the  juice  bright.  In  the  experimental 
work  a  clear  juice  was  obtained  by  filtration  through  a  felt  bag  and 
subsequent  filtration  through  cotton  fiber  pulp  filter. 

Clarification  may  also  be  accomplished  as  described  for  grape 
juice ;  that  is,  by  sterilizing  the  juice  into  glass  carboys,  allowing  it 
to  settle  several  weeks,  drawing  off  from  the  sediment,  and  filtering. 

Preparing  Filtered  Juice  for  Bottling. — The  filtered  juice  is 
bottled  in  three  forms:  (1)  natural  juice  undiluted  and  unsweetened, 
(2)  diluted,  sweetened,  and  (3)  sweetened  but  undiluted.  The  sweet- 
ened undiluted  juice  is  the  best.  Sugar  helps  to  retain  the  fresh 
berry  flavor  and  prevents  the  development  of  a  bitter,  astringent 
flavor  noticeable  in  unsweetened  juices  after  several  months  storage. 
The  amount  of  sugar  added  is  enough  to  increase  the  Balling  degree 
of  the  juice  to  about  45  per  cent,  which  is  approximately  3%  pounds 
of  sugar  to  each  gallon  of  juice.  Sweetened  loganberry  juice  is  diluted 
with  about  two  volumes  of  water  (preferably  carbonated)  when 
served. 


38  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

Bottling  and  Sterilizing. — The  bottles  are  filled  with  cold  juice  and 
capped  with  caps  sterilized  one  minute  in  boiling  water.  The  juice 
may  be  sterilized  by  heating  in  water  to  170°-175°  F  for  thirty 
minutes.  Carbonating  before  bottling  reduces  the  temperature  of 
sterilizing  and  improves  the  quality  of  the  juice. 

The  process  of  manufacture  is  very  simple ;  little  equipment  is 
needed  and  the  quality  of  the  product  is  high.  Its  manufacture  should 
therefore  prove  a  profitable  undertaking  for  growers  or  growers' 
organizations. 

POMEGRANATE   JUICE 

When  properly  made,  pomegranate  juice  is  of  a  brilliant  purplish 
red  color  and  perfectly  clear ;  its  flavor  is  pleasing  and  it  blends  well 
with  other  fruit  juices,  besides  making  a  very  pleasant  beverage  of 
itself  when  diluted  and  sweetened.  Ordinarily  it  will  be  too  tart 
and  the  flavor  is  not  retained  very  satisfactorily  unless  the  juice  is 
sweetened  before  bottling. 

Extraction  of  Juice. — The  "rag"  and  peel  of  the  pomegranate 
contains  so  much  tannin  that  juice  from  these  portions  of  the  fruit 
is  so  "puckery"  that  it  is  undrinkable.  The  desirable  juice  is  in  the 
arils  or  "kernels,"  The  problem  is  to  separate  these  from  the  peel 
and  "rag."  It  has  been  found  that  the  smallest  amount  of  tannin 
in  the  juice  and  the  largest  yield  of  juice  is  obtained  when  the  whole 
fruit  is  placed  in  a  rack  and  cloth,  or  basket  type  press,  and  pressed 
without  previous  crushing.  Yields  of  about  90  to  100  gallons  per  ton 
have  been  obtained. 

Clearing  the  Juice. — It  Avas  found  that  the  juice  could  be  easily 
clarified  by  heating,  settling,  and  filtration.  The  freshly  pressed  juice 
is  heated  to  140°-165°  F  and  allowed  to  cool  and  settle  for  24  hours. 
The  settled  juice  is  racked  from  the  sediment  and  filters  very  quickly. 
Probably  the  high  tannin  content  of  the  juice  favors  this  natural 
clarification. 

Addition  of  Sugar  and  Sterilizing. — If  the  juice  is  very  tart, 
sugar  should  be  added  to  increase  the  concentration  to  about  35°-40° 
Balling.  If  the  fruit  is  very  ripe,  sugar  addition  to  increase  the  juice 
to  30°  Balling  will  be  sufficient.  By  tests  made  upon  measured  sam- 
ples the  proper  amount  of  sugar  can  be  quickly  determined.  Roughly, 
2  to  3  pounds  of  sugar  to  each  gallon  of  juice  will  be  sufficient. 

Sweet  red  grape  juice  from  thoroughly  ripe  red  wine  grapes  and 
made  as  described  under  grape  juice  in  this  publication  may  be 
added  to  pomegranate  juice  with  pleasing  results.     The  blend  is  less 


ClRC.  313]  FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES  39 

harsh  than  the  straight  pomegranate  juice  and  has  much  more  char- 
acter than  plain  red  juice  from  wine  grapes.  E.  M.  Chace  of  the 
United  States  Department  of  Agriculture  Citrus  By-products  Labora- 
tory of  Los  Angeles  has  made  a  number  of  pleasing  combinations  of 
pomegranate  juice  with  other  juices,  especially  grape  fruit  juice. 

Bottling,  capping  and  sterilizing  at  175°  F  for  30  minutes  are 
carried  out  as  described  for  grape  juice. 


CITRUS   FRUIT  JUICES 

Citrus  juices  when  preserved  by  pasteurization  do  not  retain 
their  flavor  satisfactorily.  Heavy  sweetening,  or  concentration  before 
pasteurization,  enables  these  juices  to  better  retain  their  flavor.4 
Preservation  by  storing  in  sealed  containers  at  15°  F,  or  lower  tem- 
peratures, retains  the  flavor  very  well.  For  small  factories  or  for 
home  preparation  the  sweetened  juices  are  recommended. 

Raw  Materials. — In  citrus  districts  packing  house  culls  are 
generally  used  as  raw  material.  A  still  lower  grade  of  fruit  is  that 
known  as  "commission  merchant  culls"  that  are  left  after  the  packing 
house  culls  have  been  sorted  by  peddlers  or  commission  merchants. 
This  grade  of  culls  usually  contains  a  considerable  quantity  of  decayed 
fruit  "black  hearts"  smutty  fruit  and  fruit  otherwise  unfit  for  juice 
purposes,  This  unfit  fruit  must  be  sorted  before  it  is  used  for  juice. 
It  is  not  possible  to  prepare  a  first  class  juice  from  such  low  grade 
of  fruit. 

1 '  Grove  run ' '  fruit  is  sometimes  used  by  large  producers  of  citrus 
juices.  It  is  often  necessary  to  buy  fruit  in  this  way  to  insure  an 
adequate  supply. 

Sorting  and  Washing. — The  decayed  and  moldly  fruit  must  be 
discarded.  Washing  is  desirable  in  order  to  remove  mold  spores,  dust, 
smut  or  other  foreign  matter  adhering  to  the  skin.  This  is  done  best 
by  any  of  the  citrus  fruit  washers  used  in  packing  houses. 

Extraction  of  Juice. — Where  there  is  no  objection  to  the  presence 
of  oil  and  bitterness  from  the  peel  in  the  juice,  the  fruit  can  be  run 
through  the  machine  illustrated  in  figure  5,  which  both  crushes  and 
presses.  However,  most  consumers  do  not  like  the  strong  orange  oil 
flavor  and  bitter  taste  from  the  peels.  The  presence  of  the  oil  and 
bitterness  can  be  avoided  as  follows :  The  fruit  is  cut  in  half  and  juice 
is  extracted  by  use  of  the  revolving  cone  extractor  illustrated  in 

*  Directions  for  concentrating  fruit  juices  are  given  in:  Irish,  John  H. 
Fruit  juice  concentrates.     California  Agr.  Exp.  Sta.  Bui.  392:1-20.     1925. 


40 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


figure  23.  Extraction  with  this  device  is  called  " burring."  To 
remove  coarse  particles  of  pulp  the  juice  should  be  strained  through 
a  fine  screen  or  coarse  cheese  cloth. 

Preservation  of  Unsweetened  Juice. — If  facilities  permit,  the  juice 
should  be  treated  as  follows  in  order  to  minimize  undesirable  changes 
in  flavors:  Immediately  upon  extraction  from  the  fruit  the  juice  is 


Fig.  23. — Revolving  cone  citrus  juice  extractor. 

heated  to  180°  or  200°  F  and  then  chilled  immediately  to  40°  P,  or 
below.  This  quick  process  is  known  as  " flash  pasteurization."  The 
juice  may  be  heated  in  the  continuous  pasteurizer  (fig.  8)  and  cooled 
in  aluminum  or  tin  coils  surrounded  by  circulating  cold  brine  and 
ammonia.  Such  cooling  equipment  can  be  purchased  from  dairy 
supply  companies. 

Juice  treated  in  this  way  can  be  held  in  cold  storage  in  closed 
containers  for  several  weeks  with  but  little  deterioration.  The  taste 
of  juice  treated  in  this  manner  is  slightly  different  from  that  of  juice 
freshly  extracted  but  the  change  in  flavor  is  not  objectionable.     For 


ClRC.  313]  FRUIT    JUICES   AND    FRUIT    JUICE   BEVERAGES  41 

small  scale  production  the  flash  pasteurization  and  cooling  described 
above  are  not  feasible  and  the  sweetened  juice  process  is  recommended 
in  such  cases. 

If  cold  storage  is  available,  storage  at  a  freezing  temperature  is 
recommended.  Glass  containers  or  double  enameled  tin  cans  may  be 
used  as  containers.  These  should  not  be  filled  completely ;  considerable 
space  should  be  left  for  expansion  during  freezing.  The  hardening 
room  of  an  ice  cream  factory  or  the  freezing  storage  room  of  a  cold 
storage  warehouse  make  ideal  storage  for  citrus  juices. 

The  juice  may  be  bottled  and  pasteurized  as  described  for  apple 
juice  but  the  flaA^or  soon  deteriorates. 

Preservation  by  addition  of  one-tenth  of  one  per  cent  sodium 
benzoate  is  possible  but  is  not  recommended  except  for  low  grade 
juice  in  barrels.  One-tenth  of  one  per  cent  corresponds  to  about  7 
ounces  of  sodium  benzoate  to  50  gallons  of  juice. 

Sweetened  Citrus  Juices. — A  fairly  satisfactory  sweetened  juice 
for  the  preparation  of  beverages  can  be  prepared  by  mixing  1  part 
lemon  juice  and  3  parts  orange  juice  and  adding  about  4  pounds  of 
sugar  to  a  gallon  of  this  mixture.  To  preserve  the  juice,  bottle  it  and 
pasteurize  it  as  directed  for  apple  juice  that  is  at  175°  F  for  30 
minutes.  To  use,  dilute  with  water  to  taste.  In  general  this  method 
is  the  most  satisfactory  for  preparing  citrus  juice  beverages. 

This  product  usually  retains  a  pleasing  flavor  for  three  months  or 
longer  when  stored  at  ordinary  temperatures.  If  bottled,  pasteurized 
and  stored  at  32°  F  it  retains  its  flavor  for  at  least  a  year.  Citrus 
juices  and  syrups  are  discussed  further  in  the  next  section  of  this 
circular. 

FRUIT    JUICE    BEVERAGES 

Some  fruit  juices,  apple  and  certain  varieties  of  grapes,  are 
suitable  for  beverages  as  they  are  taken  from  the  fruit.  Others 
require  dilution  with  water  and  sweetening  by  the  addition  of  sugar 
to  make  them  into  palatable  drinks,  while  still  others  require  also 
carbonation. 

The  following  portion  of  this  publication  is  devoted  to  the 
preparation  of  beverages  from  fruit  juices  and  concentrates. 

There  is  consumed  annually  in  the  United  States  about  8,000,000,000 
bottles  of  carbonated  beverages,  or  about  80  bottles  per  capita.  Very 
little  of  this  contains  an  appreciable  proportion  of  real  fruit  juice. 
If  as  little  as  one-fourth  of  the  above  mentioned  quantity  of  carbo- 
nated beverages  were  made  from  real  fruit  juice,  there  would  not  be 


42  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

enough  cull  fruits  for  the  purpose.  The  fact  that  much  cull  fruit  is 
now  allowed  to  go  to  waste  is  proof  that  relatively  little  is  used  in 
carbonated  beverages,  Investigations  have  fully  demonstrated  the 
practicability  of  utilizing  a  larger  proportion  of  fruit  juices  in  such 
beverages  without  greatly  increasing  the  cost.  Fruit  beverages  are 
not  only  more  palatable  but  are  more  healthful  than  the  synthetic 
fruit  imitation  beverages.  In  California  at  least  there  is  no  excuse 
for  the  imitation  fruit  beverages. 

The  nature  of  the  fruit  and  the  content  of  the  juice  determine 
the  method  of  preparing  the  juice.  The  juices  of  apples  and  certain 
varieties  of  grapes  are  suitable  without  modification  for  preparation 
of  carbonated  beverages.  Others  such  as  those  from  citrus  fruits 
(grapefruit,  lemon,  lime  and  orange),  pomegranates  and  most  varie- 
ties of  berries  require  dilution  with  water  and  the  addition  of  sugar 
to  make  them  suitable  for  the  purpose. 

WATER  SUPPLY  FOR  BEVERAGES 

The  water  supply  is  often  a  source  of  trouble  in  the  preparation 
of  bottled  fruit  beverages.  Water  from  natural  sources  contains 
varying  amounts  of  dissolved  mineral  salts  and  organic  material. 
Unless  these  are  removed  natural  water  is  usually  unfit  for  use  in 
preparing  bottled  beverages  because  of  clouding  of  the  beverage 
through  precipitation  of  mineral  salts, 

There  are  a  number  of  water  purifiers  on  the  market  for  preparing 
water  for  use  in  beverages,  Most  of  these  are  satisfactory  if  properly 
operated.  A  proprietary  water  softener,  filled  with  zeolite  water 
softening  material,  has  been  used  with  Berkeley  water,  and  found 
satisfactory  for  bottled  beverages.  The  names  of  manufacturers  will 
be  sent  on  request. 

Distilled  Water. — Distilled  water  is  more  satisfactory  than 
untreated  water,  or  that  which  has  been  filtered.  A  water  still  of 
any  desired  capacity  can  be  installed  at  a  moderate  cost.  Owing  to 
the  fact  that  there  is  always  a  demand  for  distilled  water  for  use  in 
automobile  and  radio  batteries  it  is  possible  in  some  communities  to 
make  the  supplying  of  these  demands  a  profitable  side  line. 

Low  Pressure  Carbonating  System. — Many  producers  of  carbo- 
nated beverages  use  the  low-pressure  system  of  carbonating.  The 
syrup  and  water  are  mixed  in  a  large  tank  of  water  at  or  near  the 
freezing  point  of  water  32°  F.  At  this  low  temperature  the  solubility 
of  carbon  dioxide  is  much  greater  than  at  room  temperature.     Glass 


Circ.  313] 


FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES 


43 


lined  steel  tanks  are  generally  used  for  carbonating  liquids  at  low 
pressure.  This  method  greatly  simplifies  bottling  equipment  and 
operations  and  gives  a  product  of  more  uniform  character  and  gas 
pressure.    Liquids  carbonated  and  bottled  by  the  low  pressure  system 


Fig.  24. — Low  pressure  bottling  machine  and  bottle  sealer. 
(Courtesy,  Henry  Brown  Company,  Glendale,  Calif.) 


do  not  foam  so  excessively  during  bottling  as  those  carbonated  at  high 
pressure  at  room  temperature.  A  large  size  low  pressure  carbonating 
machine  is  shown  in  figure  24  and  a  carbonated  water  storage  tank 
in  figure  25. 


44 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


High  Pressure  Carbonating  System. — Most  small  producers  of 
carbonated  beverages  use  the  high  pressure  carbonating  system.  A 
high  pressure  carbonating  machine  is  shown  in  figure  26.  This  small 
carbonator  has  a  capacity  of  about  twenty  gallons  of  water  or  juice 
an  hour.     This  machine   consists  of   a  tin-lined  heavy   walled  steel 


Fig.  25. — Carbonated  water  storage  tank  and  continuous  bottle  pasteurizer. 
(Courtesy,  Henry  Brown  Company,  Glendale,  Calif.) 


cylindrical  tank  fitted  with  a  stirrer  and  a  small  force  pump.  The 
carbonating  chamber  holds  about  five  gallons  of  water.  Water  can 
be  forced  by  the  pump  into  the  cylinder  against  pressure  of  carbon 
dioxide  gas. 

Carbon  dioxide  gas  is  admitted  to  this  cylinder  from  a  cylinder 
of  the  liquified  gas  through  a  regulating  valve  by  means  of  which 
any  desired  pressure  of  gas  can  be  maintained  in  the  carbonator. 
At  the  same  time  the  water  or  the  juice  is  pumped  and  sprayed  under 


Circ.  313] 


FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES 


45 


pressure  into  the  carbonating  chamber  and  is  mixed  with  the  gas  by 
the  stirring  device.  The  pump  and  stirrer  are  operated  by  a  small 
electric  motor  which  is  controlled  by  an  automatic  switch.  The  switch 
automatically  cuts  off  the  current  to  the  motor,  when  the  carbonating 
chamber  has  been  filled  with  liquid. 


Fig.   26. — Water   softening,   carbonating,   and   bottling   equipment   used   in 
the   Fruit   Products   Laboratory,   University   of   California. 


TABLE  4 

Showing  Eelation  Between  Pressure,  Volumes  of  Gas  and  Temperature  of 
Water  in  Carbonating  Beverages 


Carbonating  pressure, 
40  pounds 

Carbonating  pressure, 
50  pounds 

Carbonating  pressure, 
60  pounds 

Carbonating  pressure, 
70  pounds 

Degrees 
Fahr. 

Volumes  of 
gas  (C02) 

Degrees 
Fahrenheit 

Volumes  of 
gas  (CO2) 

Degrees 
Fahrenheit 

Volumes  of 
gas  (CO  2) 

Degrees 
Fahrenheit 

Volumes  of 
gas  (CO2) 

32 

6  2 

32 

7.3 

32 

8  8 

32 

9  6 

40 

5  4 

40 

6.2 

40 

7.2 

40 

8  0 

50 

4  4 

50 

5  2 

50 

6  0 

50 

6  2 

60 

3.7 

60 

3  7 

60 

4  2 

60 

4.6 

70 

2  7 

70 

3  2 

70 

3  6 

70 

4  0 

46 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


There  is  a  definite  relation  between  the  pressure  (pounds  per 
square  inch)  or  of  the  volumes  of  carbonic  acid  gas  and  the  tempera- 
ture of  the  water  used  in  carbonating.     Table  4  shows  this  relation. 

An  example  will  serve  to  illustrate  its  application.  Suppose  you 
desire  about  60  pounds  pressure  in  the  carbonated  beverage.  If  the 
temperature  of  the  water  is  60°  F  then  it  will  require  4.2  volume 
of  gas. 


/JO 


/30 


-Curves  showing  rates  of  heat  penetration  and  cooling  of  bottled 
beverages. 


PRESERVATION  OF  BEVERAGES  AND  BEVERAGE  BASES 

Beverages,  syrups  and  sweetened  juices  can  be  preserved  by 
pasteurization,  cold  storage  or  preservatives.  Where  practicable, 
pasteurization  is  recommended  in  preference  to  the  other  two  methods. 

Preservation  by  Pasteurization. — Carbonated  bottled  beverages, 
owing  to  the  presence  of  carbon  dioxide,  will  not  support  mold 
growth.  This  fact  greatly  simplifies  pasteurization  as  a  temperature 
of  150°  F  is  sufficient  to  destroy  yeast,  the  only  microorganism 
capable  of  developing  in  such  beverages.    Pasteurization  is  conducted 


Circ.  313 


FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES 


47 


as  described  elsewhere  in  this  circular,  at  150°  F  for  30  minutes.  In 
the  investigations  approximately  15,000  bottles  of  carbonated  bever- 
ages were  pasteurized  in  this  manner  without  subsequent  loss  by 
molding  or  fermentation. 

Large  continuous  pasteurizers  are  used  in  large  bottling  establish- 
ments. Small  scale  bottlers  may  make  use  of  the  simple  wooden  vat 
pasteurizer  described  under  ' '  Bottle  Pasteurizers. ' ' 

TABLE  5 

Bates  of  Heat  Penetrarion  and  Cooling  of  Eight  Ounce  Bottles  of  Fruit 

Beverage 


Time  in 
minutes 

Temperature 

°F.,  of 

pasteurizer 

Temperature 

°F.,  of  bottle 

(average  of 

two  bottles) 

0 

56 

58 

5 

134 

82 

7 

152 

102 

10 

152 

122 

15 

150 

137 

20 

150 

144 

25 

150 

147 

30 

150 

149 

35 

150 

149 

37 

150 

150 

Cooling  after  pasteurizing 


0 

150 

150 

3 

146 

148 

5 

136 

146 

8 

124 

140 

10 

122 

131 

13 

106 

124 

15 

98 

118 

18 

80 

102 

20 

76 

95 

23 

68 

83 

26 

64 

77 

28 

62 

72 

30 

60 

70 

35 

57 

63 

Sweetened  juices  and  syrups  in  quart  or  smaller  containers  must 
be  pasteurized  at  175°  for  30  minutes,  and  for  60  minutes  in  gallon 
containers. 

Typical  rates  of  heat  penetration  and  cooling  are  given  in  table  5 
and  in  figure  27. 5 


s  For  further  data  on  rate  of  heat  penetration  see:  Irish,  J.  H.,  M.  A.  Joslyn 
and  J.  W.  Parcel!.  Heat  penetration  in  the  pasteurizing  of  syrups  and  concen- 
trates in  glass  containers.     California  Agr.  Exp.  Sta.  Hilgardia  7:183-206.    1928. 


48  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

Preservation  by  Cold  Storage. — All  juices  and  syrups  can  be  held 
indefinitely  in  fresh  condition  in  sealed  containers  at  0-10°  F.  Enamel 
lined  and  outside  enamel  coated  5-gallon  friction  top  cans  such  as 
shown  in  figure  28  are  very  suitable  for  the  purpose.  Paraffin  lined 
barrels  and  5-gallon  glass  carboys  can  also  be  used.  The  containers 
must  not  be  completely  filled  because  on  freezing  the  liquid  expands. 
About  10  per  cent  of  the  volume  of  the  container  should  be  allowed 
for  this  expansion. 


Fig.  28. — Five-gallon  enameled  can  for  cold-packing  fruit  juices  and  syrups. 

In  large  barrels  (25  or  50  gallons)  cooling  is  very  slow  and 
during  the  cooling  period  fermentation  may  begin.  Better  results 
are  obtained  if  the  juice  is  precooled  in  a  milk  cooler  to  40-32°  F 
before  filling  into  barrels.  It  cools  quickly  at  0-10°  F  in  5-gallon 
containers  for  which  precooling  is  not  needed. 

Preservation  by  use  of  Preservatives. — Sodium  benzoate  is  the  only 
permissible  food  preservative  that  is  practicable  for  use  in  preserving 
fruit  beverages,  concentrates,  sweetened  juices  and  syrups.  One- 
tenth  of  one  per  cent  is  sufficient.  There  is  a  popular  prejudice 
against  sodium  benzoate  and  on  this  account  pasteurization  should 
be  employed  whenever  feasible. 

Sodium  benzoate  varies  greatly  in  quality.  Some  grades  possess 
a  medicinal  "iodoform"  taste  and  odor  that  renders  it  wholly  unfit 
for  use  in  fruit  products. 


CIRC.  313]  FRUIT    JUICES   AND   FRUIT    JUICE   BEVERAGES  49 

One-tenth  of  one  per  cent  corresponds  to  about  7  ounces  of  benzoate 
to  50  gallons  of  fruit  juice ;  or  to  about  8  ounces  to  50  gallons  of  50° 
Balling  syrup.  The  benzoate  should  be  weighed  and  then  dissolved 
in  water  before  adding  to  the  fruit  juice.  A  solution  containing  one 
pound  of  benzoate  dissolved  in  water  and  diluted  with  water  to  one 
gallon  makes  a  solution  of  convenient  strength.  One  pint  of  this 
solution  contains  2  ounces  of  sodium  benzoate.  After  addition  to  the 
juice  or  syrup  the  liquid  must  be  thoroughly  stirred  to  insure  mixing. 

Carbonated  bottled  fruit  beverages  keep  satisfactorily  with  0.05 
per  cent  of  sodium  benzoate,  i.e.,  5/100  of  1  per  cent.  The  amount  of 
benzoate  necessary  to  give  this  concentration  in  the  bottled  beverage  is 
added  to  the  syrup.  Thus  if  2  ounces  of  syrup  is  used  to  a  6-ounce 
bottle,  then  the  syrup  must  contain  0.15,  or  15/100  of  1  per  cent  of 
sodium  benzoate.  The  presence  of  sodium  benzoate  must  be  printed 
in  prominent  type  on  the  label.  For  further  information  on  this 
very  important  point  write  the  State  Food  and  Drug  Laboratory, 
University  of  California,  Berkeley. 


THE  CONCENTRATION  OF  FRUIT  JUICES  FOR  USE  IN  BEVERAGESe 

Fruit  juices  can  be  concentrated  for  use  in  beverages  in  any  one 
of  several  ways,  although  for  general  use  concentration  in  vacuo  is 
the  most  suitable.  The  various  methods  are  described  in  detail  in 
Bulletin  392  of  this  Station  so  will  be  presented  here  only  very  briefly. 
The  following  methods  have  been  used  most  successfully : 

Concentration  in  Vacuo. — Concentration  at  atmospheric  pressure 
results  in  the  loss  of  flavor  and  color  and  often  in  caramelization. 
These  difficulties  may  be  avoided  by  concentrating  under  vacuum. 
Under  a  vacuum,  liquids  boil  at  lower  temperature  than  in  the  open 
and  moisture  is  removed  with  less  injury  to  the  juice.  "Vacuum 
pan"  is  the  name  applied  to  the  commercial  apparatus  utilizing  this 
principle. 

Concentration  by  the  Spray  Process. — This  process  which  is  used 
extensively  for  drying  milk,  has  been  used  successfully  for  making 
powdered  lemon  juice.  Powdered  orange  juice  was  lacking  in  flavor. 
An  excellent  grape  syrup  was  made  by  this  process.  The  process 
consists  in  spraying  the  juice  into  a  large  chamber  into  a  blast  of 
heated  air.  Drying  takes  place  almost  instantaneously.  It  is  believed 
that  the  spray  process  has  great  possibilities  as  a  means  of  concen- 
trating fruit  juices  but  further  experiments  are  necessary. 

6  Directions  for  making  fruit  juice  concentrates  have  been  given  in:  Irish, 
John  H.  Fruit  juice  concentrates.  California  Agr.  Exp.  Sta.  Bui.  392:1-20. 
1925. 


50 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


TABLE  6 

Balling  Saccharometer  Keadings  for  Sugar  Syrups  at  Various  Temperatures 

(After  J.  E.  Bell,  Oregon  Agricultural  College) 


Degree  of  concentration  desired 

Temp.  Fahr. 

10 

15 

20 

25 

30 

40 

50 

60 

70 

75 

Saccharometer  reading  at  temperature  observed 

32 

10  41 
10  37 
10.29 

10  22 
10  16 
10.08 
10  03 
10.00 
9.97 
9.92 
9.71 
9.59 
9.46 
9.32 
9.18 
9.02 
8.86 
8.68 
8.51 
8.33 
8  14 
8  04 
7.94 
7.73 
7.62 
7.51 
7.40 
"  7.29 
7.19 
7.08 
6.97 
6.86 
6.74 
6.61 
6.48 
6.36 
6.24 
6.18 
5.47 
4.82 
4  00 
3.38 
2.56 
1.74 
0  86 
0  01 

15.52 
15  44 
15  33 
15  24 
15  17 
15.19 
15  03 
15.00 
14.97 
14.91 
14.69 
14  57 
14.44 
14  30 
14.13 
13.91 
13.84 
13.67 
13.49 
13.29 
13.11 
13.01 
12.99 
12.70 
12.59 
12.48 
12.37 
12.26 
12.16 
12.06 
11.96 
11.85 
11.74 
11.61 
11.48 
11.36 
11.24 
11.12 
10.46 
9.80 
9.10 
8.61 
7.62 
6.84 
5.98 
5.13 

20.62 
20.52 
20.36 
20.26 
20.18 
20.10 
20.03 
20.00 
19.97 
19.91 
19.69 
19.56 
19.42 
19.28 
19.18 
18.97 
18.79 
18.62 
18.45 
18  27 
18.07 
17.97 
17.87 
17.66 
17.55 
17  46 
17.33 
17.22 
17.11 
17.00 
16.89 
16.78 
16.67 
16.56 
16.45 
16.34 
16.23 
16.12 
15.49 
14.86 
14.16 
13.46 
12  70 
11.94 
12.11 
10.28 

25.72 
25.59 
25.39 
25.29 
25  19 
25  10 
25.04 
25.00 
24.97 
24.90 
24.68 
24.54 
24.40 
24.24 
24.08 
23.92 
23.76 
23.59 
23.41 
23.21 
23.01 
22.91 
22.81 
22.61 
22.51 
22.41 
22.31 
22.20 
22.10 
21.99 
21.88 
21.77 
21.67 
21.56 
21.45 
21.34 
21.23 
21.12 
20.49 
19.87 
19.21 
18.54 
17.79 
17.03 
16.23 
15  46 

30.82 
30.65 
30.42 
30  31 
30  21 
30.11 
30.04 
30.00 
29.97 
29.90 
29.68 
29.54 
29.39 
29.24 
29.06 
28.92 
28.76 
28.59 
28.41 
28.21 
28.01 
27.91 
27.81 
27.61 
27.51 
27.41 
27.31 
27.20 
27.10 
26.99 
26.88 
26.77 
26.67 
26.56 
26.45 
26.34 
26.23 
26.12 
25.51 
"24.90 
24.26 
23.62 
22.90 
22.15 
21.39 
20.61 

40.98 
40.75 
40.49 
40.34 
40.22 
40.12 
40  04 
40.00 
39.97 
39.90 
39.67 
39  53 
39.38 
39.22 
39.02 
38.90 
38.72 
38.54 
38  36 
38.18 
38.00 
37.90 
37.80 
37.60 
37.50 
37.40 
37.30 
37.20 
37.09 
36.98 
36.87 
36.76 
36.71 
36.54 
36.43 
36.22 
36.21 
36.10 
35.52 
34.94 
34.34 
33.74 
33.08 
32.42 
31.65 
30 .  97 

51.11 

50.80 
50.50 
50.36 
50  23 
50  12 
50  04 
50.00 
49.97 
49.90 
49.66 
49.50 
49.34 
49  18 
49.06 
48.86 
48.70 
48  53 
48.35 
48.17 
47.99 
47.90 
47.81 
47.61 
47.51 
47.41 
47  31 
47.21 
47.11 
47.01 
46.91 
46.81 
46.70 
46.61 
46.57 
46.40 
46.29 
46.18 
45.64 
45.10 
44.57 
43.94 
43.32 
42.70 
42.03 
41.36 

61.22 
60.88 
60  54 
60.40 
60.26 
60  14 
60  05 
60.00 
59.97 
59.90 
59.68 
59  54 
59  38 
59.22 
59.12 
58.90 
58  74 
58.58 
58.40 
58.22 
58.04 
57.95 
57.86 
57.68 
57.59 
57.50 
57.40 
57.30 
57.20 
57.10 
57.00 
56.90 
56.80 
56.70 
56.60 
56.56 
56.40 
56.30 
55.79 
55.68 
54.73 
53.61 
53.18 
53.04 
52.41 
51.78 

71.25 
70.91 
70.58 
70.42 
70.28 
70.16 
70.05 
70.00 
69.97 
69.92 
69.71 
69.57 
69.42 
69.28 
69.12 
68.97 
68.81 
68.65 
68.49 
68.31 
68. 15 
68.07 
67.98 
67.80 
67.71 
67.62 
67.53 
67.44 
67.35 
67.26 
67.17 
67.08 
67.00 
66.91 
66.82 
66.73 
66.65 
66.57 
66  05 
65.73 
65.01 
64.50 
63.96 
63.42 
62.83 
62.24 

76.29 

41.    . 

75.94 

50    . 

75.61 

54     . 

75.46 

57 

75.32 

61 

75.18 

62 

75.06 

63* 

75.00 

64 

74.98 

68 

74.94 

72 

74.75 

75    . 

74.60 

79.    . 

74.45 

82     . 

74.39 

86 

74.14 

90 

74.02 

93 

73.83 

97 

73.67 

100 

73.51 

104 

108 

73.35 
73.19 

110 

73.11 

112 

73.03 

115    

72.77 

117    

72.76 

119 

72.75 

121 

72.58 

122 

72.49 

124 

72.40 

126 

72.31 

128 

72.22 

130 

72  13 

131 

72  04 

133 

71.95 

135 

71.86 

137 

71.77 

139..'. 

71.68 

140 

71.59 

149 

71.12 

158 

70.65 

167 

70.16 

176    

69.67 

185 

69.15 

194 

68.63 

203 

68.10 

212 

67.58- 

*  The  Balling  saccharometer  is  calibrated  at  about  63  degrees  Fahrenheit.  Therefore  the  figures  in 
the  columns  opposite  that  temperature  appear  as  whole  numbers  and  are  identical  with  the  degree  of 
concentration  sought  in  the  syrup  as  indicated  at  the  head  of  the  respective  columns.  The  corrected 
saccharometer  reading  will  be  higher  or  lower  as  the  temperature  varies  from  63  degrees. 


ClRC.  313]  FRUIT    JUICES   AND    FRUIT    JUICE    BEVERAGES  51 

Concentration  by  Freezing. — This  process  is  the  best  for  preserv- 
ing the  aroma  and  color  of  the  original  fruit.  It  consists  of  freezing 
the  fruit  juice  and  then  separating  the  ice  crystals  from  the  concen- 
trated juice.  Those  wishing  to  use  these  processes  in  the  preparation 
of  fruit  juices  can  obtain  detailed  information  from  the  manufacturers 
of  the  equipment.  Sometimes  equipment  can  be  adapted  to  purposes 
other  than  those  for  which  it  was  intended. 

TEMPERATURE    CORRECTION    FOR    SYRUP   TESTS 

The  temperature  at  which  fruit  juices  and  syrups  are  made  for 
preparation  of  beverages  varies.  Since  temperature  markedly  affects 
the  indicated  reading  of  hydrometers,  for  accuracy  and  uniformity 
in  the  preparation  of  beverages  it  is  necessary  to  make  corrections  for 
these  variations  in  temperature.  The  accompanying  temperature 
correction  table  for  sugar  syrups  provides  a  quick  and  fairly  accurate 
means  for  making  this  correction.  An  example  will  illustrate  the 
use  of  the  table  (table  6).  Suppose  the  bottler  desires  a  concentration 
in  the  syrup  of  50°  Balling  and  that  the  temperature  is  140°  P.  In 
the  vertical  column  under  50°  Balling  opposite  the  temperature  140°  P 
is  found  the  figure  46.18.  His  50°  Balling  syrup  will  test  46.18° 
Balling  at  140°  P,  i.e.,  he  should  make  a  syrup  testing  46.18°  Balling 
(about  46.2°  Bal.).  If  he  desires  a  syrup  which  will  test  50°  Balling 
at  a  room  temperature  of  63°  F  there  is  no  correction. 

BOTTLING    AND    SEALING    CARBONATED    BEVERAGES 

Seven  and  eight  ounce  bottles  are  the  common  sizes  for  bottling. 
Most  syrups  are  used  at  the  rate  of  one  and  one-half  fluid  ounces 
(about  45  cubic  centimeters)  to  a  bottle,  the  bottling  machine  being 
adjusted  to  deliver  this  amount  of  syrup  to  each  bottle.  Carbonated 
water  is  then  added  to  fill  the  bottle  within  about  one  and  one-fourth 
inches  of  the  top  and  the  bottle  is  immediately  sealed  with  a  crown 
cap.  Sixteen  and  thirty-two  ounce  bottles  may  be  used  for  carbo- 
nated fruit  beverages  when  the  low  pressure  carbonating  system  is 
used. 

ESTIMATED    COST    OF    PRODUCTION 

The  cost  of  producing  various  carbonated  fruit  beverages,  in  the 
Fruit  Products  Laboratory  is  summarized  in  tables  7  and  8.  The 
fruit  was  purchased  in  many  cases  in  the  wholesale  fruit  markets. 
Grapes  were  obtained  from  the  Viticulture  Division  at  the  University 
Farm,  Davis,  at  prices  prevailing  at  the  time  of  harvest. 


52 


UNIVERSITY    OF    CALIFORNIA— EXPERIMENT    STATION 


TABLE    7 
Estimated  Cost  of  Fruit  Syrups 


Cost 
of  fruit 
per  ton 

Syrup,  cost  of  one  gallon 

Fruit 

Fruit 

Sugar 

Power 
and 
labor 

Pasteur- 
izing, and 
container 

Total 
per 

gallon 

dollars 
15  00 

143  00 
50.00 
50  00 
20  00 

143  00 
20  00 
20  00 
20  00 

333  00 

205  00. 

dollars 
0.50 
0.56 
0.90 
0  63 
0  40 
0  70 
0  20 
1.20 

0  14 

1  26 
0.84 

dollars 

0 
0  34 

0 

0 
0  36 
0  30 
0  36 
0  12 
0  12 
0  34 
0  36 

dollars 
0  25 

dollars 
0.20 
0  20 
0  20 
0  20 
0  20 
0.20 
0  20 
0  20 
0  20 
0  20 
0  20 

dollars 
1  00 

0 
0 
0 
0 
0 
0 
1 
0 
0 
0 

15 
25 
25 
15 
15 
15 
00 
20 
15 
15 

1  25 

1  35 

1  08 

0  81 

1  35 

0  91 

2  52 

0  66 

1  95 

1  55 

*  Made  with  added  sugar  and  not  vacuum  concentrated, 
t  Vacuum  concentrated  3J4  to  1. 

TABLE   8 
Estimated  Cost  of  Fruit  Beverages 


Kind 


Beverage  cost  of  one  8-ounce  bottle  in  cents 


Syrup 


Labor 


Bottle* 


Pasteur- 
izing 


Label 


Total, 
with  bottle 


Total 
exclusive 
of  bottle 


Apple 

Blackberry 

Red  grape 

Muscat  grape 

Lemon 

Loganberry... 

Orange 

Pomegranate. 

Raspberry 

Strawberry 


cents 
1  25 
1.56 
1.69 
1.35 
1.01 
1.69 
1.01 
.83 
2.44 
1.94 


46 
.46 
.46 
.46 
.46 


2.5 


cents 
.5 
.5 
.5 
.5 
.5 
.5 
.5 
.5 
.5 
.5 


cents 

4  81 

5  12 
5  25 
4.91 
4.57 
5.25 
4  57 
4.39 
6.00 
5.40 


cents 
2  31 
2.62 
2.75 
2.41 
2.07 
2.75 
2.07 
2.89 
3.50 
2.90 


*  In  this  estimate  reclaimed  bottles  were  used  which  accounts  for  the  low  cost  of  this  item, 
bottles  cost  ZYi  to  4  cents  each. 


New 


Bottlers  usually  make  a  charge  to  the  customer  for  bottles  and 
cases.  In  some  instances  this  is  $1.50  per  case  of  two  dozen  bottles, 
or  at  the  rate  of  approximately  6  cents  a  bottle.  This  charge  is 
refunded  on  return  of  the  cases  and  bottles.  In  table  8  the  last 
column  represents  the  net  cost  to  the  bottler  who  prepares  his  own 
syrups.  These  figures  are,  of  course,  only  approximate ;  great  accu- 
racy is  not  claimed. 


Circ.  313 


FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES 


,>;; 


BUILDINGS  AND  EQUIPMENT  FOR  FRUIT  BEVERAGE  PRODUCTION 

Figure  29  shows  the  arrangement  of  equipment  for  convenient 
and  economical  operation  of  a  juice  plant  based  on  the  commercial 
production  of  apple  cider  pasteurized  in  bottles,  ready  to  go  to  the 
bottler  for  carbonating,  or  to  be  used  without  further  preparation, 
as  a  beverage. 


Fig.  29. — Typtical  plant  layout  for  making  fruit  juices  and  fruit  beverages 
(carbonating  equipment  omitted). 


1.  Fruit  receiving  door. 

2.  Washer. 

3.  Sorter. 

4.  Crusher  and  press. 

5.  Juice  pump. 

6.  Pomace  removal  door. 

7.  Mixing  tank. 


8.  Filter  press.  15.  Finished  product  handled 

9.  Empty  bottle  rack.  through  doorway. 

10.  Bottle  filler.  16.  Boiler  room. 

11.  Bottle  capper.  17.  Press  room. 

12.  Filled  bottle  rack.  18.  Eefining  room   (filtering, 

13.  Bottling  tank.  bottling,  etc.). 

14.  Pasteurizer. 


The  floor  plan  for  installing  the  various  pieces  of  equipment  will 
vary  according  to  the  size  of  factory,  kind  of  fruit  used,  space  avail- 
able and  many  other  conditions.  The  layout  illustrated  in  figure  29, 
therefore,  is  very  general  in  character  and  subject  to  modification 
to  suit  local  conditions.  It  has,  however,  been  so  prepared  as  to 
permit  efficient  handling  of  the  fruit  and  the  products  made  from  it. 


DEFINITION    OF   TERMS 


The  Bureau  of  Chemistry  of  the  United  States  Department  of 
Agriculture,  Food,  Drugs  and  Insecticide  Administration,  for  con- 
venience in  inspection,  has  defined  various  products.    It  is  important 


54  UNIVERSITY    OF    CALIFORNIA: — EXPERIMENT    STATION 

that  the  manufacturer  of  such  products  be  familiar  with  these  defini- 
tions. Since  regulations  are  modified  from  time  to  time  it  is  necessary 
to  keep  in  touch  with  the  administration  to  be  able  to  comply  with 
the  law. 

The  State  food  inspection  law  of  California  is  practically  the  same 
as  the  Federal  law  so  there  need  be  no  confusion  in  this  respect. 

The  laws  of  different  states  vary,  so  it  is  necessary  to  become 
familiar  with  them  if  products  are  to  be  sold  outside  of  California. 

Following  are  definitions  of  fruit  products  used  in  the  beverage 
industry. 

Sweetened  juice  is  the  name  applied  to  fruit  juice  to  which  has 
been  added  less  than  50  per  cent  of  cane  sugar.  This  is  the  form 
in  which  tart  or  sour  juices  such  as  grapefruit,  lemon,  lime,  orange, 
pineapple,  pomegranate  and  the  juices  of  various  kinds  of  berries 
are  best  for  use  in  preparing  both  still  and  carbonated  beverages. 
When  diluted  by  adding  four  or  five  parts  of  water  to  one  part  of 
sweetened  juice  the  characteristic  fruit  flavor  is  retained  and  the 
beverage  is  not  too  sweet.  Still  drinks  made  from  sweetened  juice 
are  properly  called  fruit  "ades."  Lemonade  and  orangeade  are 
familiar  examples. 

Fruit  syrup  is  the  name  applied  to  fruit  juices  to  which  have  been 
added  50  per  cent  or  more  of  cane  sugar  and  must  contain  at  least 
33 V3  per  cent  of  pure  fruit  juice. 

With  most  fruit  syrups  when  diluted  to  beverage  strength  the 
proportion  of  fruit  juice  is  low  and  consequently  the  fruit  flavor  is 
weak.  When  diluted  to  drinking  strength  the  ratio  of  sugar  to  juice 
is  too  high  and  the  taste  is  too  sweet.  Fruit  syrups  can  best  be  used 
in  soda  fountain  specialties  such  as  sundaes,  in  fruit  malts,  ice  cream 
sodas  or  for  blending  in  making  fruit  punches.  If  they  are  used  in 
bottled  carbonated  beverages  it  is  usually  necessary  to  add  fruit  acid 
to  counterbalance  the  excessive  sweetness. 

Fruit  juice  concentrate  is  the  name  applied  to  fruit  juices  which 
have  been  concentrated  by  evaporation  of  the  excess  water  under 
vacuum  or  at  atmospheric  pressure  or  by  freezing  and  subsequent 
separation  of  the  ice  and  concentrated  juice.  Citrus  juice  concen- 
trates suitable  for  use  in  beverages  are  now  available.  Several  citrus 
concentrate  factories  are  in  successful  operation  in  California.  Grape 
concentrates  of  good  quality  are  obtainable  from  several  California 
factories.  Most  of  the  apple  concentrates  on  the  market  are  made  by 
evaporating  in  the  open  at  atmospheric  pressure  and  they  conse- 
quently possess  a  cooked  taste.     Pineapple  concentrate  is  produced 


ClRC.  313]  FRUIT    JUICES   AND    FRUIT    JUICE   BEVERAGES  55 

in  limited  quantities.  In  the  Fruit  Products  Laboratory  it  has  been 
demonstrated  that  concentrates  thoroughly  satisfactory  for  use  in 
beverages  can  be  prepared  from  most  of  the  important  fruits  grown 
in  California. 

APPLE  JUICE   OR   CIDER 

Apple  juice  or  cider  is  probably  the  most  popular  fruit  juice 
consumed  in  the  United  States.  It  contains  the  proper  proportion 
of  sugar,  requires  no  sweetening  or  dilution  and  is  low  in  price.  For 
these  reasons  there  is  little  need  to  convert  it  into  "appleade"  or 
soda  water,  etc. 

"Appleale"  is  a  beverage  made  by  flavoring  apple  juice  with 
ginger  extract  or  mixing  it  with  ginger  ale  extract.  Since  the  strength 
of  ginger  extract  is  so  variable  it  is  impossible  to  give  directions  for 
the  proportions  of  cider  and  extract  required  for  the  blend.  Better 
results  are  obtained  by  mixing  equal  parts  of  apple  juice  and  ginger 
ale  of  good  quality.  Served  cold  this  mixed  drink  is  very  pleasing 
and  refreshing.  Several  imitation  "appleades"  and  synthetic  apple 
syrups  are  on  the  market  but  have  made  little  headway  against  the 
real  juice. 

CITRUS   FRUIT  JUICE    BEVERAGES 

The  only  very  successful  citrus  fruit  juice  beverages  have  been 
those  made  from  the  fresh  fruit  for  immediate  consumption.  Through 
the  efforts  of  the  California  Fruit  Growers  Exchange,  orange  juice 
extracting  machines  have  been  installed  in  most  soda  fountains  and 
thousands  of  carloads  of  cull  oranges  are  used  for  preparing  fountain 
drinks. 

Several  imitation  citrus  juice  beverages,  because  of  extensive 
advertising  are  consumed  in  large  quantities. 

Attempts  to  prepare  bottled  beverages  to  be  stored  several  months 
for  future  consumption  have  resulted  in  failure.  Many  promoters 
and  investors  have  lost  large  sums  of  money  in  attempts  to  prepare 
and  market  such  beverages.  The  cause  of  failure  is  that  discussed 
elsewhere,  namely,  that  bottled  citrus  juices  soon  deteriorate  in  flavor 
when  stored  at  room  temperature. 

An  ideal  citrus  beverage  is  one  that  possesses  all  of  the  flavor 
and  aroma  of  the  freshly  expressed  juice.  Methods  of  preparation 
should  be  such  as  to  alter  this  original  fresh  fruit  flavor  and  aroma 
as  little  as  possible.  In  most  commercial  attempts  to  prepare  such 
beverages  in  recent  years  the  lowest  possible  temperatures  that  would 
destroy  the  spoilage  organisms  have  been  employed.     However,  the 


56  UNIVERSITY   OF    CALIFORNIA EXPERIMENT    STATION 

most  serious  type  of  spoilage  in  citrus  juices  is  not  that  caused  by 
microorganisms  but  chemical  and  enzymatic  action.  The  development 
of  a  characteristic  ' '  stale  taste ' '  is  caused  by  a  chemical  change  appar- 
ently in  part  at  least  induced  by  enzymes.  Enzymes  are  substances 
that  have  the  power  of  inducing  certain  chemical  changes. 

The  enzymes  are  not  destroyed  by  the  ordinary  pasteurization 
temperatures  commonly  used  to  kill  yeasts  and  molds,  but  they  are 
destroyed  at  a  temperature  of  from  190°  to  200°  F  according  to 
experiments.  Heating  citrus  juices  to  such  a  high  temperature  in 
open  vats  causes  a  deterioration  which  is  objectionable.  This  difficulty 
can  be  overcome  by  "flash  heating,"  that  is,  by  bringing  it  to  200°  F 
by  passing  the  juice  through  a  coil  heated  by  boiling  water  and  then 
passing  through  a  cooler  to  reduce  the  temperature  of  the  juice 
immediately.  In  tests  juice  treated  in  this  way  was  held  at  room 
temperature  ten  days  without  any  noticeable  deterioration.  Tests 
have  proved  that  by  the  addition  of  1/10  of  1  per  cent  sodium  ben- 
zoate to  this  juice  it  can  be  stored  in  clean  paraffined  barrels  in  cold 
storage  at  about  32°  F  for  several  months  without  appreciable  change 
in  flavor  and  color.  It  may  be  stored  at  0°-15°  F  without  use  of 
benzoate.  Either  procedure  would  permit  bottlers  to  store  a  supply 
of  juice. 

Sweetened  orange  juice  is  prepared  from  this  treated  juice  in  the 
following  manner:  To  100  gallons  of  mixed  citrus  juices  consisting 
of  75  gallons  of  orange  juice  and  25  gallons  of  lemon  juice  is  added 
700  pounds  of  sugar  and  emulsified  orange  oil  to  flavor. 

If  to  be  stored  at  room  temperature  the  amount  of  sodium  benzoate 
must  be  increased  to  1/10  of  1  per  cent.  The  foregoing  quantity 
yields  about  155  gallons  of  "sweetened  juice"  about  49°  Balling. 

A  still  orange  beverage  is  prepared  from  the  sweetened  juice  by 
adding  one  part  of  sweetened  juice  to  four  parts  of  distilled  water. 

A  carbonated  orange  beverage  is  prepared  by  adding  iy2  ounces 
of  the  sweetened  juice  to  a  6-ounce  bottle  or  3  ounces  to  a  12-ounce 
ginger  ale  bottle.  Carbonated  distilled  water  at  30  pounds  pressure 
(about  2  volumes  of  gas)  at  40°  F  is  added  to  fill  the  bottles. 

Pasteurization  is  required  for  all  of  the  bottled  fruit  beverages 
unless  sufficient  benzoate  of  soda  is  added  to  give  1/10  of  1  per  cent 
in  the  finished  drink.  Still  beverages  must  be  pasteurized  at  175°  F 
for  30  minutes.  Carbonated  beverages  must  be  pasteurized  at  150°  F 
for  30  minutes. 

Sweetened  lemon  juice  is  prepared  in  a  manner  similar  to  that 
described  for  sweetened  orange  juice.  To  100  gallons  of  lemon  juice 
extracted  by  burring  is  added  700  pounds  of  cane  sugar  and  1/10 


ClRC.  313]  FRUIT    JUICES   AND    FRUIT    JUICE    BEVERAGES  57 

of  1  per  cent  of  sodium  benzoate.  To  this  is  added  emulsified  lemon 
oil  to  taste.  This  will  yield  about  155  gallons  of  sweetened  juice  of 
about  49°  Balling. 

A  still  lemon  beverage  is  prepared  by  adding  one  part  of  sweet- 
ened juice  to  seven  or  eight  parts  of  distilled  water. 

A  carbonated  lemon  beverage  is  prepared  by  adding  l1/^  ounces 
of  the  sweetened  juice  to  a  6-ounce  bottle,  or  3  ounces  to  a  12-ounce 
bottle  and  carbonating  at  30  pounds  pressure  (about  2  volumes  of 
gas)  at  40°  F,  using  distilled  water. 

Sweetened  grapefruit  juice  is  prepared  by  adding  to  100  gallons 
of  burred  juice  700  pounds  of  cane  sugar  and  1/10  of  1  per  cent 
sodium  benzoate.  This  will  yield  about  155  gallons  of  sweetened  juice 
of  about  49°  Balling. 

A  still  grapefruit  beverage  is  prepared  by  adding  one  part  of 
sweetened  juice  to  four  or  five  parts  of  distilled  water. 

A  carbonated  grapefruit  beverage  is  prepared  by  adding  iy2 
ounces  of  sweetened  juice  to  a  6-ounce  bottle  or  3  ounces  to  a  12-ounce 
bottle  and  carbonating  under  30  pounds  pressure  (about  2  volumes 
of  gas)  at  40°  F,  using  distilled  water. 

Tangerine  and  lime  beverages  can  be  prepared  in  the  same  manner 
as  those  from  grapefruit. 

Fruit  punches  can  be  made  by  various  combinations  of  citrus  and 
other  sweetened  juices.  One  of  the  most  pleasing  combinations 
consists  of  equal  parts  of  sweetened  orange,  lemon  and  grapefruit 
juices  with  enough  sweetened  pomegranate  juice,  blackberry  juice, 
red  grape  juice  to  produce  the  desired  color.  To  this  mixture  may 
be  added  crushed  pineapple,  shredded  orange,  bananas,  maraschino 
cherries,  berries  or  other  fruits  to  improve  the  appearance  in  the 
punch  bowl. 

Orange  concentrate  has  proved  the  most  popular  of  the  citrus 
concentrates  for  use  in  beverages.  In  fact,  it  is  the  most  extensively 
used  of  all  fruit  juice  concentrates  for  this  purpose. 

Beverages  made  from  orange  concentrate  are  preserved  by  pasteur- 
ization at  150°  F  for  30  minutes  or  by  the  addition  of  1/10  of  1  per- 
cent benzoate  of  soda. 

An  orange  syrup  suitable  for  use  by  bottlers  has  been  prepared 
commercially  as  follows : 

1  gallon  72°  Balling  orange  concentrate. 

5  gallons  of  60°  Balling  simple  syrup  (cane  sugar  and  water). 

i/4  fluid  ounce  of  terpeneless  orange  oil  (emulsified). 

1%  ounces  of  this  syrup  is  added  to  a  e^-ounce  bottle  and  car- 
bonated water  added  to  fill. 


58  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

There  are  two  types  of  carbonated  citrus  fruit  beverage : 

(1)  The  ginger  ale  type,  possessing  high  carbonation.  Water  for 
use  in  this  beverage  is  carbonated  under  30  pounds  pressure  (about 
2  volumes  of  gas)  at  40°  F.  This  beverage  is  especially  suitable  for 
mixing  with  other  drinks. 

(2)  The  low  pressure  type,  for  which  the  water  is  carbonated 
under  15  to  30  pounds  pressure  (1  to  2  volumes  of  gas)  at  50°-60°  F. 
This  beverage  is  better  than  (1)  for  drinking  unmixed  with  other 
beverages. 

Lemon  concentrate  because  of  its  high  acidity  and  distinctive 
flavor  is  one  of  the  most  satisfactory  fruit  concentrates.  The  follow- 
ing formula  has  been  found  satisfactory  for  using  lemon  concentrate : 

1  gallon  72°  Balling  freshly  prepared  commercial  lemon 

concentrate. 
20  gallons  60°  Balling  simple  syrup. 
%  fluid  ounce  of  terpeneless  lemon  oil  (emulsified). 

Lemon  beverage  is  made  by  adding :  y2  ounce  of  this  syrup  to 
each  6% -ounce  bottle  and  carbonated  water  added  to  fill.  Either  the 
high  or  low  carbonation  may  be  used  as  with  orange  beverages.  The 
beverage  is  preserved  either  by  pasteurization  or  by  sodium  benzoate. 

Where  sufficient  quantities  of  grapefruit,  limes,  tangerines  and 
other  citrus  fruits  are  available,  their  juices  can  be  concentrated  and 
used  in  a  manner  similar  to*  that  described  for  orange  and  lemon 
concentrates. 

GRAPE    JUICE    BEVERAGES 

Grapes  best  suited  for  beverages  are  described  elsewhere  in  this 
circular,  in  the  paragraph  headed  "Varieties  of  Grapes  for  Juice." 

Sweetened  grape  juice  can  be  prepared  by  adding  cane  sugar  to 
Concord  or  Isabella  or  to  mixed  Muscat  and  red  grape  juice  to  bring 
the  juice  to  45°-50°  Balling.  '  To  one  part  of  sweetened  juice  is 
added  three  parts  of  still  or  carbonated  water  if  the  juice  is  to  be 
served  as  a  fountain  drink.  If  the  juice  is  to  be  made  into  a  bottled 
beverage  about  2  fluid  ounces  is  used  to  a  6-ounce  bottle  or  2%  ounces 
to  an  8-ounce  bottle ;  and  water  carbonated  to  about  60  pounds  pres- 
sure (4  volumes  of  gas)  at  40°  F  is  added.  For  low  carbonation 
about  30  pounds  pressure  (about  2  volumes  of  gas)  at  50°-60°  F  is 
used. 

Equal  parts  Muscat  and  red  grape  juice  has  been  found  to  be 
the  best  proportions  of  the  two  juices  for  most  beverage  purposes. 
The  red  juice  should  be  high  in  acid,  that  is,  very  tart.  This  con- 
dition is  attained  if  slightly  unripe  grapes  or  a  considerable  proportion 


CIRC.  313]  FRUIT    JUICES   AND    FRUIT    JUICE   BEVERAGES  59 

of  second  crop  grapes  are  used.  If  thoroughly  ripe  Muscat  grapes 
are  used  the  blended  juices  need  not  be  sweetened.  If  sugar  is  not 
added  the  dilution  with  carbonated  water  should  be  in  the  ratio  of 
about  one  part  of  water  to  one  of  the  unsweetened  juice. 

Very  satisfactory  grape  concentrates  are  now  available  in  commer- 
cial quantities  at  moderate  prices.  These  are  prepared  in  most  fac- 
tories by  concentration  in  vacuo.  The  usual  density  is  about  70°  Ball- 
ing which  represents  a  concentration  of  about  3% :  1.  The  Muscat 
juice  should  be  concentrated  by  the  freezing  process  instead  of  by 
evaporation  in  order  that  the  volatile  flavor  may  be  retained.  If  the 
Muscat  juice  is  concentrated  by  freezing  a  concentrate  of  about 
50°-55°  Balling  only  is  obtained;  sugar  may  be  added  to  increase  the 
density  to  70°  Balling. 

In  using  the  concentrates,  1  part  of  Muscat  to  2  parts  red  juice 
concentrate  will  be  satisfactory.  The  mixture  is  diluted  to  beverage 
strength  with  4  to  5  volumes  of  water  (still  or  carbonated  according 
to  the  product  desired).  As  the  concentrates  are  usually  deficient 
in  acid  owing  to  separation  of  cream  of  tartar,  it  is  usually  necessary 
to  add  a  small  amount  of  citric  or  tartaric  acid  to  the  beverage. 

A  carbonated,  bottled,  blended  Muscat-Petite  Sirah  beverage  was 
produced  and  sold  by  the  Fruit  Products  Laboratory  for  about  a 
year  and  proved  second  in  popularity  only  to  orange  beverage.  It  is 
believed  that  this  beverage  which  was  called  Muscat  Blend  has  great 
commercial  possibilities. 

Preservation  of  Bottled  Grape  Beverages. — Bottled  grape  bever- 
ages require  pasteurization  or  addition  of  sodium  benzoate  as  described 
for  citrus  juices. 

BEVERAGES  FROM  OTHER  FRESH  FRUITS 

The  juices  of  strawberries,  loganberries,  raspberries  and  blackber- 
ries are  suitable  for  beverage  purposes.  They  have  sufficiently  high 
acidity,  low  sugar  content  and  strong  flavor  to  permit  the  addition 
of  sugar  and  dilution  with  water  and  still  make  palatable  beverages. 
Sweetened  juice  45° -49°  Balling  is  the  form  in  which  these  juices  are 
best  suited  to  the  preparation  of  beverages.  The  addition  of  1  part 
of  sweetened  juice  to  4  or  5  water  gives  a  beverage  which  is  satisfac- 
tory to  most  consumers.  The  juice  is  easily  extracted  by  crushing  the 
berries,  heating  to  150°-160°  F,  and  pressing. 

The  beverages  can  be  prepared  in  the  form  of  "ades"  by  the 
addition  of  still  water  or  they  can  be  carbonated  either  under  low 
pressure  or  high  pressure  according  to  requirements. 


60  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

The  carbonated  drinks  may  be  bottled  and  pasteurized  or  may  be 
served  as  fountain  drinks. 

Raspberry  juice  beverage  possesses  a.  very  pleasing  flavor  but  the 
high  cost  of  the  fruit  and  its  scarcity  renders  its  use  impracticable  in 
California. 

Loganberry  juice  is  available  in  quantity  at  moderate  prices, 
particularly  from  the  Pacific  Northwest.  The  high  flavor  and  acidity 
permit  sweetening  and  dilution.  Owing  to  the  loss  of  color  and 
flavor  in  unsweetened  juice  it  is  recommended  that  loganberry  juice 
be  sweetened  to  45°-50°  Balling  at  the  factory.  The  sweetened  juice 
retains  the  fresh  flavor  and  color  very  satisfactorily.  Pasteurization 
at  175°  F  is  a  satisfactory  method  of  preservation. 

Strawberry  juice  has  a  strong  characteristic  flavor  but  has  a  very 
unstable  color.  After  standing  a  few  weeks  exposed  to  light  or  at 
room  temperature  the  red  color  fades  or  changes  to  an  objectionable 
brownish  color.  If,  however,  the  juice  is  sweetened  to  45°-50°  Balling 
and  stored  at  0-10°  F  it  retains  its  fresh  color  indefinitely.  For  a 
bottled  beverage  the  strawberry  juice  should  be  mixed  with  black- 
berry juice.  The  latter  furnishes  color  without  greatly  changing  the 
strawberry  flavor.  One  part  of  sweetened  blackberry  to  3  parts 
sweetened  strawberry  make  a  satisfactory  mixture.  The  mixture  may 
be  labeled  "  strawberry  -blackberry  "  blend. 

Blackberry  juice  does  not  have  a  very  distinctive  flavor  and  there- 
fore it  has  not  been  so  popular  as  the  other  berry  juices.  It  has,  how- 
ever, a  deep  purplish  red  color  which  is  fairly  permanent  and  makes 
the  juice  valuable  for  blending  with  strawberry  juice  which  is  lacking 
in  color.    See  preceding  paragraph. 

Black  cherry  juice  has  possibilities  for  use  in  beverages  as  its 
characteristic  color  and  flavor  are  not  easily  destroyed  by  heat  and 
light.  The  deficiency  in  acidity  can  be  supplied  by  adding  citric  acid. 
To  prepare  the  sweetened  juice  crush  the  whole  cherries  and  a  few 
of  the  pits.  Heat  to  160°-170°  F  for  15  minutes.  Press  and  filter. 
Add  sugar  to  increase  juice  to  45°-50°  Balling  and  about  1  ounce 
of  citric  acid  to  the  gallon.  Use  as  previously  directed  for  other 
sweetened  juices 

Pomegranate  juice  beverage  is  popular  with  those  who  are  familiar 
with  the  fruit  and  have  learned  to  like  it.  Owing  to  the  fact  that  in 
bottled  form  the  beverage  deteriorates  in  flavor  and  color  it  is  recom- 
mended as  a  fountain  drink.  The  juice  is  extracted  by  pressing  the 
whole  uncrushed  fruit  as  described  under  "Pomegranate  juice."  The 
resulting  juice  is  made  to  35°  Balling  by  addition  of  sugar  and  is 
preserved  by  pasteurization.     Beverage  is  prepared  by  using  equal 


ClRC.  313]  FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES  61 

parts  of  sweetened  juice  and  water,  either  still  or  carbonated,  although 
it  is  generally  preferred  as  a  still  drink.  The  beverage  is  much 
improved  by  the  addition  of  grapefruit  juice  or  orange  juice  to 
furnish  flavor. 

BEVERAGES    FROM    DRIED    FRUITS 

Beverages  can  be  prepared  from  sun  dried  or  dehydrated  rasp- 
berries, loganberries,  blackberries  and  red  wine  grapes  as  follows: 
Soak  over  night  in  enough  water  to  return  to  the  fruits  the  water 
removed  in  drying.  After  thus  "refreshing"  the  dried  fruits  the 
procedure  is  the  same  as  for  fresh  fruits. 

While  beverages  of  fair  quality  can  be  prepared  from  these  dried 
fruits  they  are  less  palatable,  less  attractive  in  color  and  decidedly 
inferior  in  flavor  to  those  made  from  the  fresh  fruits. 

Raisin  beverage7  it  is  believed  has  commercial  possibilities.  It 
has  been  prepared  in  our  investigations  as  follows :  Mix  about 
50  pounds  each  of  Thompson  seedless  and  Muscat  raisins,  lightly 
crushed,  in  Muscat  raisin  seeder  rolls  or  similar  device.  Add  30 
gallons  of  water.  Heat  to  175°  F  for  10  minutes.  Allow  to  stand 
over  night.  Draw  off  the  liquid  and  press  the  raisins.  Place  the 
liquid  thus  obtained  on  a  second  lot  of  raisins  equal  in  weight  to 
about  one-half  of  the  weight  of  the  juice  and  repeat  the  extraction 
process  as  previously  described.  Continue  the  extraction  process  by 
adding  to  the  first  lot  of  raisins  extracted  a  second  lot  of  fresh  water. 
Use  this  extract  to  treat  fresh  raisins.  From  this  point  in  the  con- 
tinuous operation  of  the  process  each  lot  of  raisins  is  extracted  three 
times,  i.e.,  once  fresh  with  juice  which  has  been  in  contact  with  two 
lots  of  partially  extracted  raisins,  once  with  juice  that  has  been  in 
contact  with  one  lot  of  extracted  raisins  and  finally  once  with  fresh 
water.  In  this  manner  most  of  the  sugar  is  recovered.  The  extract 
should  test  about  50°-55°  Balling. 

A  raisin  concentrate  has  been  prepared  by  decolorizing  the  extract 
with  vegetable  charcoal  as  described  below  and  concentrating  in  vacuo 
to  65°  Balling.  The  concentrate  is  preserved  by  pasteurization  at 
175°  F  for  30  minutes.  It  is  usually  necessary  to  partially  decolorize 
the  extract  in  order  that  the  beverage  will  not  be  cloudy.  This  is 
accomplished  by  heating  the  juice  to  175°  F  for  30  minutes  with  from 
%  to  1  per  cent  by  weight  of  any  one  of  several  good  powdered  vege- 
table decolorizing  carbons  and  filtered  by  adding  y2  of  1  per  cent 
by  weight  of  diatomaceous  earth  and  passing  through  a  plate  and 
frame  filter. 


7  The  experiments  with  raisin  beverages  were  conducted  by  W.  V.  Cruess  and 
J.  G.  Brown. 


62 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


SORT 


\\  \ 


WASH 


TTT 

i;  i 


CRUSH 


HEAT 


PRESS 


HEAT 


»  SETTLE 


N 


E/LTER 


~*CONCENTEATE 

->  to  sreup 


u 


SWEETENED 
UUICE  BY 
~H    ADDIT/ON 
'■•**    OE  SUGAR 


\ 

w 


!  j 


// 


// 


BOTTLE 
AND  SEAL 


\\\ 


PASTEURIZE 
OR  STORE 
AT  FREEZING 


*  x  k 


ADD  SYBUP  TO 

SODA  WATER 

BOTTL.ES 


iJ_j 


ADD 

CARBONATED 

WATER 

rrn 


1 1  \  \ 


CROWN 
BOTTLES 


H  ! 


PA5TEURIZE 


BERRIES  AND  CHERRIES 

RED    GRAPES  - 

_  /APPLES    AND 

■ CITRUS  ERUITS  {WHITE  GRAPES 

POMEGRANATES 


Fig.  30. — Outline  of  processes  of  preparing  beverages  from  various  fruits. 


"Raisin  ale"  is  a  carbonated  beverage  made  from  the  raisin 
extract  by  flavoring  the  raisin  extract  with  ginger  ale  extract  of  high 
quality.  The  mixed  liquid  is  used  as  follows:  IV2  ounces  is  added 
to  a  6V2  ounce  bottle  and  carbonated  under  ^0  pounds  pressure 
(about  2  volumes  of  gas)  at  40°  F.  This  produces  a  highly  car- 
bonated beverage  similar  to  ginger  ale.  The  Muscat  raisin  flavor  is 
discernable. 


CIRC.  313]  FRUIT    JUICES    AND    FRUIT    JUICE    BEVERAGES  68 

Fig  beverage  can  be  made  by  the  extraction  method  described  for 
raisin  beverage.  The  fig  beverage  lacks  flavor,  but  if  mixed  with 
orange  or  other  highly  flavored  juice  it  may  have  possibilities  as  a 
health  beverage. 

Dried  prunes  have  been  used  for  preparation  of  a  beverage  by 
the  process  described  for  raisins  but  the  beverage  lacks  flavor.  When 
mixed  with  orange  juice  it  is  improved.  Owing  to  the  healthfulness 
of  prune  products  such  a  mixed  beverage  probably  has  commercial 
possibilities.  Further  investigations  are  in  progress  in  the  Fruit 
Products  Laboratory  on  prune  syrups,  prune  extracts  and  beverages. 

SUMMARY    OF    PROCESSES    OF    MAKING    CARBONATED    FRUIT 

BEVERAGES 

The  processes  of  preparing  syrups,  sweetened  juices,  concentrates 
and  carbonated  beverages  from  the  different  fruits  naturally  vary 
considerably  in  respect  to  various  important  details.  However,  it  is 
possible  to  prepare  a  condensed  set  of  general  directions  which  will 
give  a  "bird's-eye  view"  of  the  steps  recommended  for  the  prepara- 
tion of  the  more  important  bottled  carbonated  beverages.  This  has 
been  done  in  the  accompanying  diagram,  figure  30. 

FIRMS   SUPPLYING    FRUIT  JUICE   AND    BEVERAGE    EQUIPMENT 

For  the  convenience  of  those  interested  in  the  preparation  of  fruit 
juices  or  beverages  from  fruit  juices  the  following  list  of  firms  is 
given : 

General  Equipment — 

Anderson-Barng-rover  Mfg.  Co.,  20  Fremont  Street,  San  Francisco,  Calif. 

Hydraulic  Press  Mfg.  Co.,  Mt.  Gilead,  Ohio. 
Crushers  and  Presses — 

California  Press  Mfg.  Co.,  1800  Folsom  Street,  San  Francisco,  Calif. 

Hydraulic  Press  Mfg.  Co.,  Mt.  Gilead,  Ohio. 

Enterprise  Mfg.  Co.,  Philadelphia,  Pa. 
Filters — 

Cellulo  Filter  Co.,  Sandusky,  Ohio. 

John   Mulhern  Co.,   182  Second   Street,   San   Francisco,   Calif. 

Hydraulic  Press  Mfg.  Co.,  Mt.  Gilead,  Ohio. 

Karl  Kiefer  Mfg.  Co.,  Cincinnati,  Ohio. 

Philipp  Wirth,  332  Spring  Street,  New  York  City,  N.  Y. 

D.  R.  Sperry  &  Co.,  Merchants  Exchange  Bldg.,  San  Francisco,  Calif. 
Glass-enameled  Equipment — 

Pfaudler   Co.,   Rochester,   N.   Y.,   and   57   New   Montgomery   Street,   San 
Francisco,  Calif. 

The  Glasscote  Company,  Euclid   (Cleveland),   Ohio. 


64  UNIVERSITY    OP    CALIFORNIA EXPERIMENT    STATION 

Glass  Manufacturers — 

Illinois-Pacific   Glass   Co.,   San  Francisco,   Calif. 

Pacific  Coast  Glass  Co.,  San  Francisco,  Calif. 

Owens  Glass  Co.,  Sheldon  Bldg.,  San  Francisco,  Calif. 

McLaughlin  Glass  Co.,  Los  Angeles,  Calif. 

Southern  Glass  Co.,  Los  Angeles,  Calif. 
Filtering  Materials — 

Celite  Products  Co.,  San  Francisco,  Calif. 
Pasteurizers — 

Hydraulic  Press  Mfg.   Co.,  Mt.  Gilead,  Ohio. 

Modern  Machinery  Co.,  Wilmington,  Del. 
Vacuum  Pans — 

Concentrators  Co.,  216  Pine  Street,  San  Francisco,  Calif. 

Pfaudler  Co.,  Rochester,  N.  Y. 

Oakland  Copper  and  Brass  Works,  1346  Seventh  Street,  Oakland,  Calif. 

The  Glasscote  Co.,  Euclid   (Cleveland),  Ohio. 
Soda  Fountain  and  Bottlers'  Supplies — 

Eng-Skell  Co.,  208  Mission  Street,  San  Francisco,  Calif. 

Magnus  Fruit  Products  Co.,  301  Howard  Street,  San  Francisco,  Calif. 

Sierra  Club  Beverage  Co.,  Inc.,  Glendale,  Calif. 

John  Mulhern  Co.,  182  Second  Street,  San  Francisco,  Calif. 
Trade  Journals — 

Pacific  Bottler,  57  Post  Street,  San  Francisco,  Calif. 

The  Beverage  Journal,  431  South  Dearborn  Street,  Chicago,  111. 

The  Beverage  News,  21  Spruce  Street,  New  York  City,  N.  Y. 

The  Fruit  Products  Journal  and  American  Vinegar  Industry,  31  Union 
Square,  New  York  City,  N.  Y. 


COMPANIES    DEALING    IN    FRUIT  JUICES   AND    FRUIT  JUICE 
CONCENTRATES 

Apple  Juice — 

Adelanto  Fruit  Products  Co.,  4094  Mission  Road,  Los  Angeles,  Calif. 

Macomber  Orchard  Co.,  Sonora,  Calif. 

Martinnelli,   Watsonville,  -Calif. 
Citrus  Juices  and  Concentrates — 

The  Exchange  Orange  Products  Co.,  Ontario,  Calif. 

The  Exchange  Lemon  Products  Co.,  Corona,   Calif. 

California    Crushed    Fruit    Corporation,    1600    E.    Sixteenth    Street,    Los 
Angeles,  Calif. 

Oscar  Bulger  Co.,  San  Diego,  Calif. 
Grape  Juices  and  Concentrates — 

The  California  Grape  Products  Co.,  Ukiah,  Calif. 

Italian  Vineyard  Co.,  Los  Angeles,  Calif. 

Guasti  Grape  Products  Co.,  Los  Angeles,  Calif. 

Italian  Swiss  Colony,  Asti,   Calif. 

A.  Joseph  Co.,  Fresno,  Calif. 

National  Fruit  Products  Co.,  Lodi,  Calif. 

Golden  Gate  Grape  Juice  Co.,  San  Francisco,  Calif. 


